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1 Puo. AD-A267 AD - Form Approved 592 ION,u. PAGE MBlNo.o mstr cvom epre.,.r(udrng ihe ti,.' rev~ew.n inslrcuct~ns, seardw q ls PtIIlllt l tllill 111lililt il I. ', )':r IIIIIIJflh~tlthI HIIII ffl fl3 fl tleclion Cf in om atc i %end cormm ent, r ~qardonq th,, b rden. 'm ate Or. Sa,.nqo,oh era 'oee Oftis n eao... uarl,%o,,,... D eo~raot t -o r info rm.,o n 00.oo op... sndrdo, '. 15 e o n. / taerment and ucet. PaPerwork Re0,ct1On Pro;ect (0704-?88 ',,VV45hmsigon, CC AGENCY USE ONLY (Leave blank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED h MAY UXS/DISSERTATION 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS Synthesis, Reactivity, and Characterization of ( - Hexacarbocyclic) Manganese Dicarbonyl Complexes with Sulfur and Phosphorus Ligands 6. AUTHOR(S) Jeffrey Lynn Moler 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) B. PERFORMING ORGANIZATION REPORT NUMBER AFIT Student Attending: Univ of Iowa AFIT/CI/CIA D 9. SPONSORINGFITMONITORSNG5AGTNpYTNAME(S)NAND0AcNRE)43-SANADE(EX S[L U.6SPSPONSORING/MONITORING C DEPARTMENT OF THE AIR FORCE EL CT uqlcy REPORT NUMBER 2950 P STREET AG6 1 WRIGHT-PATTERSON AFB OH Sr 11. SUPPLEMENTARY NOTES 12a. DISTRIBUTION / AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE Approved for Public Release IAW Distribution Unlimited MICHAEL M. BRICKER, SMSgt, USAF C'hief Administration 13. ABSTRACT (Maximum 200 words) SUBJECT TERMS 15. NUMBER OF PAGES PRICE CODE 17. SECURITY CLASSIFICATION 18. SECURITY CLASSIFICATION 19. SECURITY CLASSIFICATION 20. LIMITATION OF ABSTRACT OF REPORT OF THIS PAGE OF ABSTRACT NSN F,0-550() Standard Form 298 (Rev 2-89) if'rtotb.'d b AN1,I 'td 149'18

2 SYNTHESIS, REACTIVITY, AND CHARACTERIZATION OF (i-hexacarbocyclic)manganese DICARBONYL COMPLEXES WITH SULFUR AND PHOSPHORUS LIGANDS by Jeffrey Lynn Moler An Absact Of a thesis submitted in partial fulfillment of the requirements for the Doctor of Accesion For Philosophy degree in Chemistry in the Graduate College of NTIS CRA&M The University of Iowa DTIC TAB ] Unannounced 9 May 1993 Justiuication Thesis supervisor: Associate Professor Darrell P. Eyman By Drstribution I Avaldbdity Codes Dist Avdil arid Ior special lyrc QUtA= IN a 3 lom

3 ABSTRACT A series of (,i 5 -pentamethylbenzyl)mn(co) 2 PR 3 complexes has been synthesized. Phosphine ligand substitution increases the electron density on the manganese, enhancing the nucleophilicity of the exocyclic methylene of the 1i 5 -benzyl complexes. The exocyclic methylene reacts with electrophiles to form C-C bonds with CH 3 I and PhC(O)CI and C-I bonds with 12. (71 5 -C 6 Me 5 CH 2 )Mn(CO) 2 PMe 3 (2b) reacts with Mn(CO) 5 Br to form [(,q 6 -C 6 Me 5 CH 2 Mn(CO)S)Mn(CO) 2 PMe 3 ][PF 6 ], after metathesis with [NHJ][PF 6 ], and with (i 7 5 -C 5 H 5 )Fe(CO) 2 1 to form [(iq 6 --C 6 Me 5 CH 2 FeCp(CO)2)Mn(CO) 2 PMe 3 ]I. The i 5 -benzyl complexes react by a radical pathway with the halocarbons CCI 4, CDCI 3, and CHBr 3 to form new C-C bonds at the exocyclic methylene. ESR studies support a proposed radical mechanism in these reactions. The solid-state structure of 2b is reported. A series of ( 5 -pentamethylbenzyl)manganese dicarbonyl phosphite complexes have been synthesized. Manganese-coordinated phosphites react with the exocyclic methylene of the coordinated pentamethylbenzyl ligand generating either benzyne or a carbene, an ii 6 -hexaalkylbenzene, and dialkyl- or diaryl phosphonate complexes. Their decomposition to phosphonates was observed under reduced pressure or in the presence of olefins. Benzyne, from the triphenylphosphite complexes was observed indirectly through the formation of diphenylene. The production of methylene carbenes was observed by the formation of ethene and cyclopropanes. The generation of olefins or cyclopropanes indicated that ethylidene was produced. The solid-state structure of lid is reported.

4 2 The reaction of (j 6 -C 6 Me 6 )Mn(CO) 2 SC(S)H with [Ph 3 C][BF 4 ] affords the adduct [( 6 -C 6 Me 6 )Mn(CO) 2 SCHSCPh 3 ][BF4 (52). Reaction of 52 with aniline, diethylamine, and :ert-butylamine produces [(,i 6 -C 6 Me 6 )Mn(CO) 2 SCHNEt 2 l[bf4] (53), [f(t 6 -C 6 Me 6 )Mn(CO) 2 SCHNHPhJ[BF 4 ], and [(q 6 1 -C 6 Me 6 )Mn(CO) 2 SCHNH-t-BuJ[BF 4 ], respectively, which were characterized by FTIR, FAB-MS, and 'H and 1 3 C NMR spectroscopies. The mass spectra of these complexes and [(( 6-C6Me6Mn(CO)2)2(W_- 2-SC(S)H)]+ have been investigated using FAB-MS/MS. The solid state structure of 53 is reported. Abstract approved: Thesis supervisor Title and department Date

5 SYNTHESIS, REACTIVITY, AND CHARACTERIZATION OF (T-HEXACARBOCYCLIC)MANGANESE DICARBONYL COMPLEXES WITH SULFUR AND PHOSPHORUS LIGANDS by Jeffrey Lynn Moler A thesis submitted in partial fulfillment of the requirements for the Doctor of Philosophy degree in Chemistry in the Graduate College of The University of Iowa May 1993 Thesis supervisor: Associate Professor Darrell P. Eyman I I I i

6 Graduate College The University of Iowa Iowa City, Iowa CERTIFICATE OF APPROVAL PH.D. THESIS This is to certify that the Ph.D. thesis of Jeffrey Lynn Moler has been approved by the Examining Committee for the thesis requirement for the Doctor of Philosophy degree in Chemistry at the May 1993 graduation. Thesis committee: The~s" superviso / Member Member

7 To Jeanette, Alexandria, and Cassiopeia ii

8 I have seen all things that are done under the sun, and behold, all is vanity and a chase after wind. What is crooked cannot be made straight, and what is missing cannot be supplied. Though I said to myself, "Behold, I have become great and stored up wisdom beyond all who were before me in Jerusalem, and my mind has broad experience of wisdom and knowledge ", yet when I applied my mind to know wisdom and knowledge, madness and folly, I learned that this also is a chase after windi Qoheleth 1:14-1:17 Iiiie

9 ACKNOWLEDGMENTS The United States Air Force and the Air Force Institute of Technology, Civilian Institutions Program for the opportunity and as the principal source of funding. Darrell P. Eyman for support and guidance. The members of the Eyman group and many others for the interesting discussions and enjoyable conversations. Steven J. Schauer for his initial contributions to this area of research. Norman C. Baenziger for his assistance in learning X-ray diffraction analysis. The Office of Research and Educational Development at the University of Iowa for partial support of research performed at the High-Field NMR Spectrometer Facility and High-Resolution Mass Spectrometry Center at the University of Iowa (HRMSCUI). Diane J. Lamb for obtaining accurate mass and peak matching spectral results at HRMSCUI. Larry Mallis for obtaining FAB-MS/MS spectra at HRMSCUI. The Bruker WM-360 NMR spectrometer and the Enraf-Nonius CAD-4 diffractometer were purchased in part with funds from the National Science Foundation (CHE and CHE , respectively). Accurate mass spectral results from the Midwest Center for Mass Spectrometry were partially supported by the National Science Foundation, Biology Division (Grant No. DIR ). iv

10 TABLE OF CONTENTS Page LIST OF TABLES... LIST OF FIGURES... LIST OF SCHEMES... LIST OF SYMBOLS... LIST OF ABBREVIATIONS... LIST OF NOMENCLATURE AND ENUMERATIONS... x xiv xvi xvii xviii xix INTRODUCTION... 1 CHAPTER Historical... 1 I. GEN'ERAL PROCEDURES... 7 Introduction... 7 Experimental... 7 General Methods... 7 Instrumentation... 8 Infrared Spectroscopy... 8 Nuclear Magnetic Resonance Spectroscopy... 8 Mass Spectrometry... 9 X-ray Crystallography... 9 UV-Visible Spectroscopy... 9 Electrochemistry Organometallic Reagents Mn(CO)Br [(,/q-cqme.6mn(co)3][pf(] (1) [(i6--mef)mn(co)2(pr3)i[pf6] (R = P(n-Bu) 3 (1a), PMe3 (Ib), PPh 3 (Ic), P(OMe) 3 (1d), P(OPh) (1e)) 12 ( -CýMeCQ)Mn(CO') (2*). 14 (0,q-6Me 6 )Mn(CO) 2 SC(S)H (21)...14 Inorganic and Organic Reagents K[SC(S)H] (C930)3P... ( D50)15 15 (15 V

11 Solvents Deuterated Solvents General %olvents II. PREPARATIO:,, CHARACTERIZATION, AND REACTIVITY OF (n 5 -C 6 Me 5 C i )Mn(CO)2PR 3 (R = n-bu, Me, Ph, OMe, OPh). CRYSTAL STRUCTURE OF (i 5 7 -C 6 Me 5 CH 2 )Mn(CO) 2 PMe introduction Experimental Deprotonation of Mono-substituted Phosphine Complexes (n 5.- C 6 Me 5 CH 2 )Mn(CO) 2 PMe 3 (2b) (, --C 6 Me 5 CH 2 )Mn(CO),P(n-Bu) 3 (2a) (,q 5 -C 6 Me 5 CH 2 )Mn(CO) 2 PPh 3 (2c) (1-5 -C 6 Me 5 CH 2 )Mn(CO) 2 P(OMe) 3 (2d) ( 15 -C 6 Me 5 CH 2 )Mn(CO) 2 P(OPh) 3 (2e) Reactions of [NH 4 ][PF6] with Complexes 2a-e Reactions of PhC(O)Cl with Complexes 2a-e [(i7 6 -C 6 Me 5 CH 2 C(O)Ph)Mn(CO) 2 P(n-Bu),][PF 6 ] (4a) [(7 6 -C 6 MesCH 2 C(O)Ph)Mn(CO) 2 PMe 3 ][PF 6 ] (4b) [(, 1 6 -C 6 Me 5 CH 2 C(O)Ph)Mn(CO) 2 PPh 3 ][PF 6 ] (4c) ((1 6 -C 6 Me 5 CH 2 C(O)Ph)Mn(CO) 2 P(OMe) 3 ]Cl (4d) [070-C 6 MesCH 2 C(O)Ph)Mn(CO)2P(OPh) 3 ]Cl (4e) C 6 Me 5 CH 2 C(O)Ph Reactions of CH 3 1 with Complexes 2a-e [(, 6 --C 6 MesEt)Mn(CO) 2 P(n-Bu) 3 1[PF 6 ] (Sa) [(16 -C 6 Me 5 Et)Mn(CO) 2 PMe 3 ][PF 6 ] (5b) [(n 6 -C 6 MesEt)Mn(CO) 2 PPh 3 1[PF 6 ] (5c) [( C 6 Me Et)Mn(CO) 2 P(OPh) 3 ][PF 6 ] (5e) CH 3 1 and 2b in the Presence of KH CH 3 I and 2d (,q6--c6me5et)mn(co)2p(o)(oi~e)2 (6) Kinetic Measurements of Reactions of CH 3 1 with 2a--e Reactions of 12 with Complexes 2a-e [(, 6 -C 6 MesCH 2 I)Mn(CO) 2 P(n-Bu) 3 1[PF 6 ] (7a) [(7, 6 -C 6 MesCH 2 l)mn(co) 2 PMe 3 ][PF6] (7b) [(i 6.-C 6 Me 5 CH 2 l)mn(co) 2 PPh 3 ]I (7c) [( 6 7 -C 6 Me 5 CH 2 I)Mn(CO) 2 P(OMe) 3 ][PF 6 ] (7d) [( 1 --C 6 MesCH I)Mn(CO) 2 P(OPh) 3 1] (7e)... (i?--c 6 Me 5 CH 2 I)Mn(CO).P(O)(OMe) 2 (8) Reactions of Mn(CO) 5 Br and (C;HS)Fe(CO) 2 I with Complex 2b... [(t. -C6Me5CH2FeCp(CO)2)Mn(CO)2PMe3]I (9) [(0-.C 6 Me 5 CH 2 Mn(CO) 5 )Mn(CO) 2 PMe 3 ][PF6] (10) General Procedure for the Reactions of Bu 3 SnH with Complexes 2a-e Reactions of CHBr with Complexes 2a-e (t6-c6me( 4 &2CHBr 2)Mn(CO) 2 Br (12) vi

12 Reactions of CCI 4 or CDCI 3 with Complexes 2a and 2b (1 6 --C 6 Me 5 CH 2 CCl 3 )Mn(CO)2CI (13) Reaction mixture of 2a + CDCI Reaction mixture of 2b + CDCI (,q 6 -C 6 Me CH 2 CDCl 2 )Mn(CO) 2 C1 (14) X-ray Data Collection, Solution, and Refinement of 2b Results and Discussion Synthesis and Characterization of 2a-.e Crystallographic Study of 2b General Reactivity of 2a-e Nucleophilic Reactions of 2a-e Reactions of 2b with Mn(CO) 5 Br and CpFe(CO) Radical Reactions of 2a-e ESR Studies of the Reactions of 2, 2a, and 2b with CCi Electrochemical Studies of 2a-e and Conclusions Il1. THE FORMATION OF BENZYNE AND FREE CARBENES FROM COORDINATED PHOSPHITE ESTER LIGANDS IN (i5-c 6 Me 5 CH 2 )Mn(CO) 2 PR 3 (R = OEt, OMe, OPh) Introduction Experimental Preparation of Mono-substituted Phosphite Cationic Complexes [(,4 6 -C 6 Me 6 )Mn(CO) 2 P(OEt) 3 ][PF 6 ] (21a) [(--C 6 Me 6 )Mn(CO) 2 P(OCD 3 ) 3 ][PF6J (21b) [(, --C 6 Me 6 )Mn(CO) 2 P(OC 6 D 5 ) 3 ][PF 6 ] (21c) Synthesis of Starting Materials for Cross-over Experiment [( 6 _-C- 6 H 5 Me)Mn(CO) 3 ][PF 6 ] (22a) [( C 6 DsCD3)Mn(CO) 3 ][PFd (22b) [(,q 6 -C 6 HsMe)Mn(CO) 2 P(OPh) 3 ][PFd (23a) [(,q -C 6 DsCD 3 )Mn(CO) 2 P(OC 6 Ds) 3 1[PFd (23b) D.-protoat on 0? Mono-substituted Phosphite Complexes (71 5 -C 6 Me 5 CH 2 )Mn(CO) 2 P(OEt) 3 (24a) ( C 6 Me 5 CH (V 2 )Mn(CO) 2 P(OCD 3 ) 3 (24b) 5 -qme5ch2)mn(co)2p(oc6d5)3 (24c) Reactions of Phosphite Derivatives (q 6 -CqMe R)Mn(CO)4P(O)(OR')2 (R = Me, R'-=*Et (a); R = R Me (26b); R = CH 2 D, R' = CD 3 (26c); R - Me, R'= Ph (26d); R = CH 2 D, (.q R' = C,6D5 (2.6e)) (175-CMesCH2)Mn(CO)2P(OEt)3 (24a) (7 5 --C 6 Me 5 CH 2 )Mn(CO) 2 P(OMe) 3 (2d/24b) ( --C 6 Me 5 CH 2 )Mn(CO) 2 P(OPh) 3 (2e/24c)... Calculation of Theoretical Intramolecular Distances in 2d and 2e Results and Discussion... Synthesis and Characterization of 24a--c Conversion of Phosphites into Dialkyl- and Diaryl Phosphonates.. Reactions of Triphenylphosphites Reactions of Trimethylphosphites... Reactions of Triethylphosphite vii

13 Conclusions IV. CRYSTAL STRUCTURE OF (0 5 -C 6 Me 6 H)Mn(CO).P(OMe) Introduction Experimental Synthesis of lid endo--('n5-r6me H)Mn(CO)2P(OMe)3 (1 ld) Solid State Structure ofendo-(-t-c6me 6 H)Mn(CO) 2 P(OMe) 3 (lid) Collection and Reduction of X-ray Data Results and Discussion Crystallographic Study of lid Conclusions V. REACTIONS OF [( 6 -C_ 6 Me 6 )Mn(CO) 2 (1i7-SCHSCPh 3 )][BF 4 ]: FAST ATOM BOMBARDMENT TANDEM MASS SPECTROMETRY OF DITHIOFORMATE AND THIOFORMAMIDE COMPLEXES. CRYSTAL STRUCTURE OF [(t Me 6 )Mn(CO) 2 SCHNEt 2 ][BF4] Introduction Experimental Synthe... ss (52)... [06-C6Me6)Mn(CO)20) I-SCPFiCPh)] [BF4] (52) [,(q--c6me6)mn(co)2schn" 2)][BF4I (53) [(,17--Me 6 )Mn(CO) 2 SCHN" iph][bf 4 J (54) [(0'--C 6 Me 6 )Mn(CO) 2 SCHNH(t-Bu)]IBF4I (55) [(,4 6 -C6Me6)Mn(CO) 2 CN - CPh 3 ][BF 4 ] (57) Solid State Structure of [(71--CqMe 6 )Mn(CO) 2 SCHNEt 2 ][BF Collection and Reduction of X-ray Data Results and Discussion General Discussion Synthesis and Characterization of [(1t 6 --CMe 6 )Mn(CO) 2 SCHSCPh 3 ][BF4] (52) 128 Reactions of [(17 6 -C 6 Me 6 )Mn(CO) 2 SCHSCPh 3 I[BF4] (52) with... Amines Synthesis and Characterization of [( _ 6 Me6)Mn(CO)SCHNEt 2 I[BF4] (53) Syntheses and Characterization of [0( 6 1 -CMe6)Mn(CO) 2 SCHNHPhJ[BFI (54) and [01 6 C 6 Me 6 )Mn(CO) 2 SCHNH(t-Bu)I[BF4t (55) Reactions of [( C 6 Me6)Mn(CO) 2 SCHSCPh 3 J[BF 4 ) (52) with Alcohols Reaction of [(0 1 6-C6Me6)Mn(CO) 2 SC(SCPh3I[BF4I (52) with BH Reaction of [0(i-C, 6 Mei)Mn(CO) 2 SCHSCPh 3 I[BF 4 ] (52) with BEt 3 H Synthesis and Characterization o: [Mn 2 ( C 6 Me6)2(CO) 4 S 2 CH]+ (56) FAB Tandem Mass Spectrometry viii

14 Crystallographic Study of [(,0 6 -C 6 Me 6 )Mn(CO) 2 SCHNEt 2 ][BF4] (53) Conclusions APPENDIX A. APPENDIX B. APPENDIX C. APPENDIX D. SUPPLEMENTAL TABLES FOR PHOSPHINE DERIVATIVES OF MANGANESE COMPLEXES SUPPLEMENTAL TABLES AND FIGURES FOR THE CRYSTAL STRUCTURE AND MOLECULAR MODELING OF (i 1 5 -C 6 Me 5 CH 2 )Mn(CO) 2 PMe SUPPLEMENTAL TABLES AND FIGURES FOR THE CRYSTAL STRUCTURE OF end&-(0 5 -C 6 Me 6 H)Mn(CO) 2 P(OMe) SUPPLEMENTAL TABLES AND FIGURES FOR THE CRYSTAL STRUCTURE OF [(,q 6 -CMe 6 )Mn(CO) 2 SCHNEt 2 j[bf 4 ] REFERENCES ix

15 LIST OF TABLES Table Page 1. IR and 'H NMR Spectral Data for Mn(CO)sBr and Inorganic and Organic Reagents Organometallic Reagents Deuterated Solvents General Solvents "p 1 [H) NMR and IR Spectral Data for (-q 5 -C 6 Me 5 CH 2 )Mn(CO) 2 L (2a-e) H NMR Spectral Data for ( 7 5 _-CqMe 5 CH 2 )Mn(CO) 2 L (2a-e) ' 3 CI'H) NMR Spectral Data for (q 5-4CMe 5 CH 2 )Mn(CO) 2 L (2a-e) HREI-MS Data for (u/ 5 --CMeSCH 2 )Mn(CO) 2 L (2a-e) IR Spectral Data for [(iq 6 -C 6 Me6)Mn(CO) 2 L][PF 6 ] (la-e) IR Spectral Data for [(i 6 -C 6 Me 5 CH 2 C(O)Ph)Mn(CO) 2 L]X H NMR Spectral Data for [( C 6 Me 5 CH 2 C(O)Ph)Mn(CO) 2 L]X p1h} NMR Data for [(iq 6 -- Me 5 CH 2 C(O)Ph)Mn(CO) 2 L]X HRFAB-MS Data for [(,q 6 -CqMe 5 CH 2 C(O)Ph)Mn(CO) 2 L]X C['H) NMR Data for [(t'6-4mesch 2 C(O)Ph)Mn(CO) 2 P(OPh) 3 ]CI Spectral Characterization of C 6 Me 5 CH 2 C(O)Ph IR Spectral Data for [(iq'-cqme 5 Et)Mn(CO) 2 LJX H NMR Spectral Data for [( '6-CMeSEt)Mn(CO) 2 L]X P[IH) NMR Data for [(,q 6-4MesEt)Mn(CO) 2L]X HRFAB-MS Data for [(q 6 -C 6 Me 5 Et)Mn(CO) 2 L]X C[1H) NMR Spectral Data for [(iq6--meset)mn(co) 2 L]X x

16 22. Spectral Data for [(i7 6 -C 6 Me 6 _.Et,)Mn(CO) 2 LJ[PF 6 ] IR Spectral Data for [(q 6 --C 6 MesCH 2 D)Mn(CO) 2 L]X 'H NMR Spectral Data for [(i7 6 -C 6 MesCH 2 1)Mn(CO) 2 L]X p[ih) NMR Data for [(t 1 6 -C 6 MeSCH 2 I)Mn(CO) 2 L]X HRFAB-MS Data for 1(,q 6 -C 6 Me 5 CH 2 1)Mn(CO) 2 LIX C[IH) NMR Spectral Data for [(i 1 6-4C6Me 5 CH 2 1)Mn(CO) 2 PMe 3 ][PF 6 ] (nb) Spectral Data for [(t 7 6 -C 6 MesCH 2 FeCp(CO)2)Mn(CO) 2 PMe 3 ]I Spectral Data for [(,7 6 -CMe 5 CH 2 Mn(CO) 5 )Mn(CO) 2 PMe 3 ][PF 6 ] IR Spectral Data for endo--(q 5 -C 6 Me 6 H)Mn(CO) 2 L (lla-e) IR Spectral Data for (i7 6 -C 6 Me 5 CH 2 R')Mxi(CO) 2 X (12-14) IH NMR Spectral Data for (t 1 6 -C 6 Me 5 CH 2 R')Mn(CO) 2 X (12-14) HRFAB-MS Data for (iq 6 --C 6 Me 5 CH 2 CHBr 2 )Mn(CO) 2 Br C IH) NMR Spectral Data for ( 1 6 -C 6 Me 5 CH 2 R')Mn(CO) 2 X (13, 14) Crystallographic Data and Refinement Parameters for 2b a Selected Bond Distances (A) and Angles (a) for 2b Electrochemical and Rate Data for ( 5 -CýMesCH 2 )Mn(CO)2PR 3 (2a-e) IR Spectral Data for 2la-23b P(IH) NMR Spectral Data for 21a-23b IH and 2 H NMR Spectral Data for 21a-23b C{IH) NMR Spectral Data for 21a-23b HREI-MS Data for 21a-c and 22b P[IH) NMR and IR Spectral Data for 24a--2b 'H and 2H NMR Spectral Data for 24a-c C{'H) NMR Spectral Data for 24a-c HREI-MS Data for 24a-c xi

17 P{'Hj NMR and IR Spectral Data for 26a-e IH and 2 H NMR Spectral Data for 26a-e C['H) NMR Spectral Data for 26a-e HREI-MS Data for 26a-e Crystallographic Data and Refinement Parameters for.d Selected Bond Distances (A) and Angles (*) for lid Infrared Stretching Bands for 'H NMR Data for C(IH} NMR Data for HRFAB-MS Data for IH NMR and IR Spectral Characterization Data for Crystallographic Data and Refinement Parameters for 53 a Abundant Ions in the FAB-MS/MS Spectrum of Abundant Ions in the FAB-MS/MS Spectrum of Abundant Ions in the FAB-MS/MS Spectrum of Abundant Ions in the FAB-MS/MS Spectrum of Abundant Ions in the FAB-MS/MS Spectrum of Abundant Ions in the FAB-MS/MS Spectrum of Selected Bond Distances (A) and Angles (o) for IH and 13 C{'H) NMR Spectral Data for la-e Comparison of Infrared Carbonyl Stretching Bands for la-e, lla-e, 2a--e S. 31 P NMR Data for la-.e and lla-e Complete Crystallographic Data and Refinement Parameters for 2b Fractional Coordinates and Isotropic Thermal Parameters for Hydrogen Atoms of 2b Additional Supplemental Bond Distances (A) and Angles (*) for 2b xii

18 72. General Displacement Parameter Expressions a - U's for 2b General Displacement Parameter Expressions a - B's for 2b Deviations a from Least-Squares-Planes Analysis for 2b Calculated FOFC's (x 10) for 2b Complete Crystallographic Data and Refinement Parameters for lid a Fractional Coordinates and Isotropic Thermal Parameters for lid a Fractional Coordinates and Isotropic Thermal Parameters for Hydrogen Atoms of lid Additional Supplemental Bond Distances (A) and Angles (*) for lid General Displacement Parameter Expressions a - U's for lld General Displacement Parameter Expressions a - B's for lid Deviations a from Least-Squares-Planes Analysis for lid Calculated FOFC's (x 10) for lid Complete Crystallographic Data and Refinement Parameters for 53 a Fractional Coordinates and Isotropic Thermal Parameters a for Fractional Coordinates and Isotropic Thermal Parameters for Hydrogen Atoms of Additional Supplemental Bond Distances (A) and Angles (0) for General Displacement Parameter Expressions a - U's for General Displacement Parameter Expressions a - B's for Deviations a from Least-Squares-Planes Analysis for Calculated FOFC's (X 10) for xiii

19 Figure LIST OF FIGURES Page 1. Plot of log([2b]/[2b 0 j) vs. time to calculate the pseudo-first-order rate constant for the reaction of 2b and CH 3 I at 25 C Plot of ([2b] 1 - [2bo]- 1 ) vs. time to calculate the second-order rate constant for the reaction of 2b and CH 3 I at 25 C ORTEP drawing of 2b: (a) canted side view and (b) bottom view ORTEP drawing of 2b orthogonal side views MO diagram for the interaction of transition metals and cyclohexadienyl ligands (ref 44 and 43) Molecular orbital interactions involving the manganese and ui 5 -cyclohexadienyl-exo-ene ligand ESR spectra for (a) 2a in THF and (b) 2a + CC14 in THF, both at 77 K Plot of ESR signal intensity of 2a + CCI 4 in THF vs. time Oxidation potentials (O) and carbonyl stretching frequencies vs. Tolman electronic factors (x) for (q 5 -C 6 Me 5 CH 2 )Mn(CO) 2 PR 3 (2a-e) Proposed paths for 'H- 31 P coupling through (a) the ir-carbocyclic system and (b) the manganese d4 orbital to the exocyclic methylene protons ORTEP drawings of lid with 25% probability ellipsoids: (a) side view and (b) top view ORTEP drawing of lid: orthogonal side views IH- 13 C Coupling of SCHS (6 221) and ring methyls (6 16.8) in 52 in (a) 13 C['H) and (b) 13 C NMR Spectra Low-energy collision spectrum of 51 (m/z 351) Low-energy collision spectrum of 52 (m/z 593) Low-energy collision spectrum of 53 (m/z 390) Low-energy collision spectrum of 54 (m/z 410) Low-energy collision spectrum of 55 (m/z 390) xiv

20 19. Low-energy collision spectrum of 56 (m/z 623) ORTEP drawing of 53 with 25% probability ellipsoids ORTEP drawing of 53 with 25% probability ellipsoids (bottom view) Molecular model of 2b based on crystallographic parameters Stereoscopic view of the unit cell of 2b Stereoscopic view of 2b (single molecule) ORTEP drawing of lid with hydrogen atoms: (a) canted side view and kb) top view Stereoscopic view of the unit cell of lid ORTEP drawing of 53 showing planarity of arene ring and SCHNEt 2 moiety Stereoscopic View of the unit cell of xv

21 LIST OF SCHEMES Scheme Page I. Synthesis of [( 6 7 -C 6 Me6)Mn(CO) 3 J[PF 6 ] II. Nucleophilic reactions of 2a-e III. Radical and other reactions of 2a-e IV. Proposed radical pathways for 2a-e and halocarbons V. Proposed decomposition pathway for (, 5 -C 6 Me 5 CH 2 )Mn(CO) 2 P(OC 6 DS) VI. Proposed decomposition pathway for ( C 6 Me 5 CH 2 )Mn(CO) 2 P(OCD 3 ) VII. Proposed decomposition pathway for (q 5-4-6Me 5 CH 2 )Mn(CO) 2 P(OEt) VIII. Synthesis of [( 6 -C 6 Me 6 )Mn(CO) 2 SCHNRR'][BF4] compounds xvi

22 LIST OF SYMBOLS amu... Atomic Mass Units A... Angstr6m 5... Chemical Shift S Degree of Angle C... Degrees Celsius, Centigrade K... Degrees Kelvin S... g... L... Faraday Grams Liters #g... Micrograms IL... Microliters Amol... Micromoles mg... Milligrams ml... Milliliters mm u... Milli Mass Units mmol.... M... ppm... Millimoles Molar, Moles per Liter Parts per Million cm Wavenumbers xvii

23 LIST OF ABBREVIATIONS n-bu....- (CH2)3CH3 t-bu... -C(CH 3 ) 3 Cp... 4S-C 5 H 5 Cp* C (CH 3 )s CV... Cyclic Voltammogram DPPE... (C 6 H 5 ) 2 PCH 2 CH 2 P(C 6 H5)2 DEPE....(C 3 2)2PCH 2 CH 2 P(CH 2 CH3)2 EI-MS... Electron Impact Mass Spectrometry Et... -CH 2 CH 3 FAB-MS... FTIR... Fast Atom Bombardment Mass Spectrometry Fourier Transform Infrared Mc(n)... ((-c(cnh.- 7,.)Mn(CO) 2 Me CH 3 Mr(n)... MS/MS... [016--q(CH3),)Mn(CO)2]+ Tandem Mass Spectrometry Mz(n)... [V 5 -Cq(CH 3 ) 3 (CH 2 )]Mn(CO) 2 NMR... Nuclear Magnetic Resonance Ph H5 i-pr... THF... UV-Vis... -C 2(L..3)2 Tetrahydrofuran Ultraviolet-Visible xviii

24 Compd No. LIST OF NOMENCLATURE AND ENUMERATIONS Conipd Name, Formula 1 (,q 6 -hexamethylbenzene)manganese tricarbonyl hexafluorophosphate, [(u, 6 -CMed)Mn(CO) 2 PMe 3 IIPF 6 Jl la lb ic ld le (jq 6 -hexamethylbenzene)manganese dicarbonyl tri-n-butylphosphine hexafluorophosphate, [(q~ 6 -C, 6 Me 6 )Mn(CO) 2 P(n-BU) 3 1[PF 6 ] (no-hexamethylbenzene)mangancse dicarbonyl trimethyiphosphine hexafluorophosphate, [(,i 6 -C 6 Me 6 )Mn(CO) 2 PMe 3 l[pf 6 J (iq' 6 -hexamethylbenzenc)manganese dicarbonyl triphenyiphosphine hexafluorophosphate, I(,q 6 -C 6 Mec,)Mn(CO) 2 PPh 3 JIPF 6 J (,q 6 -hexamethylbenzene)manganese dicarbonyl trimethyiphosphite hexafluorophosphate, [(,q 6 -C 6 Me6)Mn(CO) 2 P(OMe) 3 J[PF 6 I (ij 6 -hexamethylbcnzenc)manganese dicarbonyl triphenyiphosphite hexafluorophosphate, [(iq 6 -C 6 Me 6,)Mn(CO) 2 P(OPh) 3 J[PF6I 2 (il 5 -pentamethylcyclohexadienyl--exo-ene)manganese tricarbonyl, (ii 5 -C 6 Me 5 CH 2 )Mn(C0) 3 2a (j1 5 -pentamethylcyclohexadienyl-.exo-ene)manganes dicarbonyl tri-n-butylphosphine, (ij 5 -C 6 Me 5 CH2)Mn(CO) 2 P(n-BU) 3 2b (iv 5 -pentamethylcyclohexadienyl--exo-ene)manganesc dicarbonyl trimethyiphosphine, (ti 5-4Me5CH 2 )Mn(CO) 2 PMe 3 2c (iq 5 -pentamethylcyclohexadicnyl-exo-ene)manganese dicarbonyl triphenyiphosphine, (-q 5 -C 6 Me 5 CH 2 )Mn(CO) 2 PPh 3 2d (iq 5 -pentamcthylcyclohexadicnyl-.exo-ene)manganese dicarbonyl trimetbyiphosphite, (iv 5 -CMe 5 CH 2 )Mn(CO) 2 P(OMe) 3 2e (iq 5 -pentamethylcyclohexadienyi-,exo-ene)manganese dicarbonyl triphenyiphosphite, (il 5 -C 6 Me 5 CH 2 )Mn(CO) 2 P(OPh) 3 4a (i9 6 -methyl phenyl ketone pentamethylbenzene)manganese dicarbonyl tri-n-butylphosphine hexafluorophosphate, [(, 6 _C 6 Me 5 CH 2 C(O)ph)Mn(CO) 2 P(n-BU) 3 1 [PF6I xix

25 4b 4c 4d 4e (i7 6 -methyl phenyl ketone pentamethylbenzene)manganese dicarbonyl trimethyiphosphine hexafluorophosphate, [(i 7 6 -C 6 MesCH 2 C(O)Ph)Mn(CO) 2 PMe 3 IIPF6I (iq 6 -methyl phenyl ketone pentamethylbenzene)manganese dicarbonyl triphenyiphosphine hexafluorophosphate, [(,l 6 -C 6 MesCH 2.C(O)Ph)Mn(CO½2PPh 3 JIPF~J (, 6 -methyl phenyl ketone pentamethylbenzene)manganese dicarbonyl trimetbyiphosphite chloride, t(e'-c 6 Me5CH 2 C(O)Pb)Mn(CO) 2 P(OMe) 3 ]1C (,4 6 -methyl phenyl ketone pentamethylbenzene)manganese dicarbonyl triphenyiphosphite chloride, [(,q 6 -C 6 Me 5 CH 2 C(O)Ph)Mn(CO) 2 P(OPh) 3 ]Cl Sa ~(,q6-ehylpentamethylbenzene)manganese dicarbonyl tri-n-butylphosphine hexafluorophosphate, [(11 6 -C 6 Me 5 Et)Mn(CO) 2 P(n-BU) 3 J[PF 6 ] 5b (,q 6 -ethy'iic.-tamethylbenzene)manganes dicarbonyl trimethyiphosphine hexafluorophosphate, [(ii 6 -qmeset)mn(co) 2 PMe 3 J[PF 6 J sc Se (Qj 6 -ethylpentamethylbenzene)manganese dicarbonyl triphenyiphosphine hexafluorophosphate, [0i 7 6 -C 6 Me 5 Et)Mn(CO) 2 PPh 3 I[PF 6 1 (ti 6 -eothylpentamethylbenzene)manganese dicarbonyl triphenyiphosphite hexafluorophosphate, [(4~ 6 -C 6 Me 5 Et)Mn(CO) 2 P(OPh) 3 J[PF 6 J 6 (i7 6 -ethylpentamethylbenzene)manganese dicarbonyl dimethyl phosphonate, (tj 6-4Me 5 Et)Mn(CO) 2 P(O)(OMe) 2 7a (ij'-iodomethylpentmethylbenzene)manganese dicarbonyl tri-n-butylphosphine hexafluorophosphate, [(n 6 -C 6 MeSCH 2 CH 2 1)Mn(CO) 2 P(n-BU) 3 JIPF 6 J 7b (i1 6 -iodomethylpentamethylbenzene)manganese dicarbonyl trimethyiphosphine hexafluorophosphate, [(Q7 6-4C 6 Me 5 CH 2 CH 2 I)Mn(CO) 2 PMe 1 [PF 6 I 7c (V 6 -iodomethylpentamethylbenzene)manganese dicarbonyl triphenyiphosphine iodide, [(71 6 -C 6 Me 5 CH 2 CH 2 I)Mn(CO) 2 PPh 3 JI xx

26 7d 7e (iq 6 -iodomethylpentamethylbenzene)manganese dicarbonyl trimethyiphosphite hexafluorophosphate, [(,4 6 -C 6 Me 5 CH 2 CH 2 I)Mn(CO) 2 P(OMe) 3 J [PFdI (17 6 -iodomethylpentamethylbenzene)manganese dicarbonyl triphenylphosphite iodide, [(t 1 6 -C 6 Me 5 CH 2 CH 2 I)Mn(CO) 2 P(OPh) 3 J1 8 (,q 6 -iodomethylpentamethylbenzene)manganese dicarbonyl dimethyl phosphonate, (il 6 -C 6 Me 5 CH 2 CH 2 I)Mn(CO) 2 P(O)(OMe) 2 9 (,4 6 -(Methyl)iron(tq 5 -cyclopentadienyl) dicarbonyl pentamcthylbenzene)manganese dicarbonyl trimethyiphosphine iodide, I(,, 6 -C 6 Me5CH 2 FeCp(CO) 2 )Mn(CO) 2 PMe 3 JI 10 (,4 6 -(methyl)manganese pentacarbonyl pentamethylbenzene)manganese dicarbonyl trimethyiphosphine hexafluorophosphate, [(,i 6 -C 6 Me5CH 2 Mn(CO)5)Mn(CO) 2 PMe 3 J [PF 6 J 11 endo-(iq 5 -hexamethylcyclohexadienyl)manganese tricarbonyl, endo-(i7 5 -C 6 Me 6 H)Mn(CO) 3 11la endo-(q~ 5 -hexamethylcyclohexadienyl)manganese dicarbonyl tri-n-butylphosphine, endo-(,i 5 _C fme 6 H)Mn(CO) 2 P(n-BU) 3 lib endo-(,q 5 -hexamethylcyclohexadienyl)manganese dicarbonyl trimethyiphosphine, endo-(q 5 -C 6 Me 6 H)Mn(CO) 2 PMe 3 11c endo-(,q 5 -hexamethylcyclohexadienyl)manganese dicarbonyl triphenyiphosphine, endo-qi'-c 6 Me 6 H)Mn(CO) 2 PPh 3 lid endo-(iq 5 -hexamethylcyclohexadienyl)manganese dicarbonyl trimethyiphosphite, endo-(iq 5-4Me 6 H)Mn(CO) 2 P(OMe) 3 lie endo-(iq 5 -hexaxnethylcyclohexadienyl)manganese dicarbonyl triphenyiphosphite, endo-(i 7 5 -CQ 6 Me 6 H)Mn(CO) 2 P(OPh) 3 12 (?7 6-2,2-dibromoethylpentamethylt..izene)manganesc dicarbonyl bromide, (7' 6 -C 6 Me 5 CH 2 CHBr 2 )Mn(CO) 2 Br 13 (tl 6-2,2,2-trichloroethylpentamethylbenzene)manganese dicarbonyl chloride, (q 6-4Me 5 CH 2 CCl 3 )Mn(CO) 2 Cl 14 (,q 6-2,2-dichloro-2-deuteroethylpentamethylbenzene)manganese dicarbonyl chloride, (n~ 6 -CMe 5 CH 2 CDC1 2 )Mn(CO) 2 CI 21a (.q6-hcxamcthylbenzene)manganese dicarbonyl triethyiphosphite hexafluorophosphate, [(iq' 6 -C 6 Me 6 )Mn(CO) 2 P(OEt) 3 J(PF 6 I xxd

27 21b 21c 22a 22b 23a 23b (17 6 -hexamethylbenzene)manganese dicarbonyl 4.-trimethylphosphite hexafluorophosphate, [(t, 6 -C 6 Me 6 )Mn(CO) 2 P(OCD 3 ) 3 11PF 6 I (i1' 6 -hexaniethylbenzene)manganese dicarbonyl d,. 5 -triphenylphosphite hexafluorophosphate, [(', 6 -C 6 Me6dMn(CO) 2 P(OC 6 Dsi) 3 1[PF 6 j (tj 6 -toluene)mnanganese tricarbonyl hexafluorophosphate, [(i, 6 -C 6 HsMe)Mn(CO) 3 1[PF6J (i7 6 -d 8 -toluene)manganese tricarbonyl hexafluorophosphate, [(~ 1 6 -C 6 D 3 CD 3 )Mn(CO) 3 1[PF 6 ] (tq 6 -toluene)manganese dicarbonyl triphenyiphosphite hexafluorophosphate, [Oq 6 -C 6 H5Me)Mn(CO) 2 P(OPh) 3 ][PF 6 J (11 6 -ds-toluene)manganese. dicarbonyl d, 5 -triphenylphosphite hexafluorophosphate, [(ii 6 -C, 6 DsCD 3 )Mn(CO) 2 P(OC 6 D5) 3 J[PF 6 J 24a (i7 5 -pentamethylcyclohexadienyl1-exo--ene)manganese dicarbonyl triethyiphosphite, (,q'-c 6 Me 5 CH 2 )Mn(CO) 2 P(OEt) 3 24b (17 5 -pentamethylcyclohexadienyl-.exo-ene)manganese dicarbonyl 4g-trimethyiphosphite, (j7 5 -C 6 Me 5 CH 2 )Mn(CO) 2 p(ocd 3 ) 3 24c (ij 5 -pentamethylcyclohexadienyl-.exo-ene)manganese dicarbonyl d, 5 -triphenylphosphite, (n 5 -C 6 Me 5 CH 2 )Mn(CO) 2 P(OC 6 D 5 )3 25a (71 5 -cyclohexadienyl1-exo-ene)manganese dicarbonyl triphenyiphosphite, ('4 5-4C 6 H 5 CH 2 )Mn(CO) 2 P(OPh) 3 25b (tl 5 -cyclohexadienyli-exo-ene)manganese dicarbonyl d, 5 -triphenylphosphite, (ij 5-4D 5 CD 2 )Mn(CO) 2 P(0C 6 D 5 ) 3 2Ua 26b 26c (i7 6 -hexamethylbenzene)manganese dicarbonyl diethyl phosphonate, (71 6 -C 6 Me 5 Et)Mn(CO) 2 P(O)(OEt) 2 (y 6 -hexamethylbenzene)manganese dicarbonyl dimethyl phosphonate, (iq' 6-4C 6 Me 6 )Mn(CO) 2 P(O)(OMe)3 ( deuteromethylpentamethylbenze ne manganese dicarbonyl d 6 -dimnethyl phosphonate, (7'5-C 6 Me, 411-D)Mn(CO) 2 P(Q)(OCD 3 ) 2 26d (17 6 -bexamethylbenzene)manganese dicarbonyl diphenyl phosphonate, (.q 6 _C 6 Mee,)Mn(CO) 2 P(O)(OPh)3 26e( deuteromethylpentamethylbenzene)manganese dicarbonyl d 10 -diphenyi phosphonate, (-q 6 -C 6 Me 5 CH 2 D)Mn(CO) 2 P(O)(0C 6 D 5 ) 2 xxii

28 51 (i7 6 -hexamethylbenzene)manganese dicarbonyl dithioformate, (iq 6 -C 6 Me 6 )Mn(CO) 2 SC(S)H 52 (iq 6 -hexavmethylbenzene)manganese dicarbonyl triphenylmethyl dithioformate ester tetrafluoroborate, [(ti 6 -C, 6 Me 6,)Mn(CO) 2 (SCHSCPh 3 )J[BF4I 53 (11 6 -hexamethylbenzene)manganese dicarbonyl N,N-diethylthioformamide tetrafluoroborate, [(i7 6 -C 6 Me6)Mn(CO) 2 (SCHNEt2)][BF4] S4 (1 6 -hexamethylbenzene)manganese cicarbonyl N-phenylthioformamide tetrafluoroborate, [(i, 6 -C 6 Me 6 )Mn(C0½2(SCHNHPh)IIBF4I 55 (i7 6 -hexamethylbenzene)manganese dicarbonyl N-tent-butylthiofornnamide tetrafluoroborate, [(n 6 -C 6 Me( 6 )Mn(CO) 2 (SCHNH(t-Bu))J[BF 4 ] 57 (ii 6 -hexamethylbenzene)manganese dicarbonyl triphenylisonitrile tetrafluoroborate, [(ii 6 -C 6 Me. 6 )Mn(CO) 2 CNCPh 3 J[BF4] 58 manganese pentacarbonyl dithioformate, Mn(CO) 5 SCH(S) 59 (i~ 5 -pentamethylcyclopentadienyl)iron dicarbonyl dithioformate, Cp*Fe(CO) 2 SCH(S) - Manganese Pentacarbonyl Bromide, Mn(CO)SBr xxiii

29 INTRODUCTION Historical The chemistry of (arene)manganese carbonyl complexes has been studied since 1960, when Wilkinson and co-workers first reported the preparation of [( C 6-6 )Mn(CO) 3 ]X complexes, structure 1.1 Derivatives of the cationic <ýýýýmen (L = CO, CN, C(O)NHR, I an +M CONHNH2, C(O)OMe, NCO, Me, Ph, C(O)Me, """I ',,-C(O)Ph, halide, PR 3 ; 0 mx- n=o, 1, 3,5,6; m = O, 1) I (17 6 -arene)manganese tricarbonyl complexes have been formed by substitution of one carbonyl by nucleophilic anions such as cyanide, 2 alkyls, 3 aryls, 3 acyls, 3 N-alkyl carboxyamides, 4 carboxyhydrazide, 4 isocyanate, 4 and carboalkyloxides. 5 These complexes, (q 6 -arene)mn(co) 2 L, are isoelectronic with the analogous iron complexes, CpFe(CO) 2 L. The syntheses of (q 6 -arene)manganese dicarbonyl halides, hydride, and alkyls were reported by Eyman and co-workers. 6 These complexes can be used as the starting materials for synthesizing a wide range of derivatives in nucleophilic substitution reactions paralleling those observed for the iron analogues. Phosphines can be substituted for one of the carbonyls in the (,6 -arene)manganese tricarbonyl

30 2 complexes by first oxidizing the carbonyl.7, 8 Numerous studies of the reactivity of cationic (qj 6 -arene)manganese tricarbonyl complexes have been reported.1,2,3,7,8, 9 Nucleophilic attack at the arene ring which results in the formation of neutral (17 5 -cyclohexadienyl)manganese tricarbonyl complexes, structure II, has been an important theme in these papers. The chemistry of mono-substituted phosphine (tq 5 -cyclohexadienyl)manganese dicarbonyl complexes has also been studied. 8 One consequence of the manganese tricarbonyl research was the identification of (,15-C 6 Me 5 CH 2 )Mn(CO) 3, structure 11, formed in a deprotonation sidereaction in the synthesis of the cyclohexadienyl complexes by Eyman and co-workers. 10 R Men flr' Men-,--; Mn oc"'/ " L... 0c 0 IR Mn III The deprotonation of coordinated arenes to form a reactive exocyclic methylene, which can be subsequently alkylated using a wide variety of reagents, provides a useful synthetic tool. Early work on chromium carbonyl complexes of toluene and ethylbenzene revealed an area of chemistry with great potential for the derivatization of coordinated arenes. 11 The deprotonation of CpFe(arene) complexes by strong bases was reported concurrently. 12, 13 Conjugation with strained ring systems, fluorene 12,13c or carbazole, 13 c or heteroatoms (0, S, or N) 13c was found to stabilize the deprotonated CpFe(arene) complexes. However, it was not until the synthesis and

31 3 characterization of CpFe 1 (Q 5 -C 6 MesCH 2 ),1 4 structure IV, by an X-ray crystal structure that the exocyclic methylene was observed by Astruc and co-workers. These complexes were made by 02 oxidation of the Fe(I) complexes or deprotonation of the Fe(II) complexes. 14a -~-CH2 Fe Cr 4Q> 0 IV V The configurations of the i-q-benzyl complexes, resulting from the deprotonation of coordinated arenes, provide part of the explanation for the observed reactivity of these complexes. Alternatively, the crystal structure reported for the deprotonated CpFe+(fluorene) reveals that the arene, after removing a proton, remains nearly planar. 12 The planarity was explained by proposing a zwitterionic structure. The K+[(,q 6 -C 6 MesCH 2 -)Cr(CO) 3 J complex, structure V, was proposed to have a localized charge on the exocyclic methylene by Yaouanc et al. 15 However, a stable exocyclic double bond was formed by the deprotonation of CpFe(t76-triphenylniethane) The exocyclic methylene found by Astruc was kinetically stabilized by the permethylation of the arene. 1 4a Permethylation, for the same reason, allows many of the precursors and products to be thermally stable. The exocyclic methylene acts as a neutral nucleophile rather than a carbanion in most reactions. Although it is not a zwitterion, it can form zwitterions after reacting with C02, CS 2, and metal carbonyls.

32 4 The chemistry of the q 5 -pentamethylcyclohexadienyl-exo-ene ligand, or more commonly the "ti 5 -pentamethylbenzyl" ligand, was extended using manganese as the metal ion by LaBrush et al. 10 LaBrush found that [(i 6 --CMe 6 )Mn(CO) 3 J[PF6] could be deprotonated using KH or other strong bases to form an il 5 -benzyl complex, (t, 5 -C 6 Me 5 CH 2 )Mn(CO) 3, structure III, similar to that observed by Astruc. And indeed, this complex underwent many of the nucleophilic reactions that had been observed by Astruc. Its reactivity was not as great as that observed for the iron complexes, evidenced by the lack of reaction with other organometallic complexes such as Mn(CO) 5 Br and CpFe(CO) 2 CI. However, it did apparently undergo radical reactions with halocarbons. The goal of the work reported in Chapter II was to increase the nucleophilic reactivity of the exocyclic methylene. This led to the syntheses of the (9 5 -pentamethylbenzyl)manganese mono-substituted phosphine complexes. The (i7 5 -C 6 Me 5 CH 2 )Mn(CO) 2 PR 3 (R = n-bu, Me, Ph, OMe, OPh) complexes, structure III, exhibit greater reactivity than the manganese tricarbonyl complex. 16 The mono-phosphine substituted complexes form in solution in the presence of KH or other strong bases. The greater reactivity derived from phosphine substitution is demonstrated by the (i76-c 6 Me 5 CH 2 )Mn(CO) 2 PMe 3 complex, which forms bimetallic complexes in reactions with Mn(CO) 5 Br and CpFe(CO) 2 I. In addition, these monophosphine-substituted q 5 -benzyls undergo all of the reactions displayed by the manganese tricarbonyl q 5 -.benzyl complex. Carbenes and benzyne were found to be generated from the phosphite ester substituted (iq 5 -pentamethylbenzyl)manganese complexes. These phosphite ester complexes were observed to undergo a chemical reaction under reduced pressure (_ 10-3 torr) to form (17 6 -hexamethylbenzene)manganese dicarbonyl dialkyl- and diaryl phosphonates, structure VI. This reaction was shown to involve the abstraction of

33 5 hydrogen from the alkyl or aryl substituent of the coordinated phosphite ligand resulting in the formation of carbenes or benzyne and a coordinated dialkyl- or diaryl-substituted phosphonate ligand. The results of these studies are reported in Chapter III. Mn oc""'c P(OR) 2 II 0 0 VI Manganese dithioformates and thioformamides have been utilized in industrial metal treatments 17 and as additives in natural gas fuels, 18 and reported as potential lubricants. 19 The synthesis and reactivity of (17 6 -arene)manganese dicarbonyl i7 1 -dithioformate compounds, structure VIII, was reported by Schauer et al.2 0 One of Mn Mn c 1 ".1 Is 0 S 0 c''' C0 -+-" L' C VinI H H Ix the goals of our research was to study the reactions of the (1 6 -arene)manganese

34 6 dicarbonyl n'-triphenylmethyl dithioformate ester complex with nucleophiles. Subsequently, we reported the metal-mediated conversion of an i7 1 -dithioformate into thio-c 1 ligands, including thioformamides and alkanethiolates, structures IX.2 1 These reactions have potentially useful synthetic applications in thioderivatization. Previously, potassium dithioformate has been used to form thioformamide derivatives of proteins to better understand their chemical and physical properties. 22

35 7 CHAPTER I GENERAL PROCEDURES Introduction A variety of spectroscopic and spectrometric techniques are available to aid in the identification of organometallic I coordination compounds. The techniques used in our studies are described. The laboratory preparations that have been changed or improved are reported. Tables are provide that list the various solvents, reagents, and compounds used and their sources. Experimental General Methods Reactions and recrystallizations were performed under dinitrogen or argon using either standard Schlenk or glovebox techniques. 23 The glovebox, manufactured by Vacuum Atmospheres Corporation, provided a dry, inert atmosphere of dinitrogen or argon for the transfer and manipulation of air- and water-sensitive complexes. Solvents were dried over suitable reagents and freshly distilled under nitrogen.24 Tetrahydrofuran was distilled from potassium/benzophenone or molten potassium. Tetrachloromethane and dichloromethane were distilled from phosphorus pentaoxide. Hexane was distilled from calcium hydride. Solvents were further deoxygenated prior to use by multiple freeze-pump-thaw cycles or by bubbling dinitrogen or argon through the solution. Glassware was heated to a minimum of 130 C and vacuum-purged prior to use. Solid compounds were deoxygenated by multiple vacuum-purge cycles before

36 8 use. Untreated silica gel ( mesh) was used for liquid chromatography purification of products. Dimanganese decacarbonyl was typically sublimed at 47 C (1.33 x 10-1 Pa) and stored in an inert atmosphere at -15 C prior to use; however, the purity of Mn(CO) 5 Br produced from the sublimed material was the same as obtained using the unsublimed Mn 2 (CO)I 0 reagent. Trimethylamine-N-oxide was prepared by azeotropic distillation with benzene to remove waters of hydration, followed by vacuum pumping, and storage in a desiccator. Immediately prior to use, potassium hydride was washed three times with a minimum of 30 ml of dry hexane to remove mineral oil, then hexane was removed under reduced pressure. Insrmetation Infrared Spectroscopy. Infrared spectroscopy was used for the characterization and identification of compounds and monitoring of reactions, where the intensities of the carbonyl bands indicated the progress of the reaction. Infrared spectra were obtained on a Mattson Cygnus 25 FTIR spectrometer. The spectrometer was computer controlled and purged with dry, carbon dioxide-free air. The solution spectra were obtained using 0.5 mm potassium bromide cells, and solid state spectra, using KBr mull and press techniques. The solution cell was purged with inert gas prior to injection of the sample. Nuclear Magnetic Resonance Spectroscopy. 1H, 2 H, 1 3 C, ' 3 C{IH}, and 3 1 P NMR spectra were recorded on either a Bruker AC-300 or WM-360 spectrometer. 'H, 2 H, 1 3 C, and 1 3 C{'H) NMR shifts are reported with respect to Me 4 Si (6 0.0 ppm). 31 P NMR shifts are reported with respect to an external standard, H 3 PO 4 (85 %) (6 0.0 ppm). All downfield chemical shifts are positive. Spectra were obtained from samples

37 9 dissolved in an appropriate solvent, in 5 mm glass NMR tubes. Mass Spectrometry. High resolution accurate mass measurements were obtained using a VG ZAB-HF mass spectrometer in the FAB ionization mode. A VG Trio-3 tandem mass spectrometer was used to obtain FAB-MSIMS spectra.2 5 The Mn complexes were dissolved in neat 3-nitrobenzyl alcohol (NBA) and placed on a standard stainless-steel FAB probe tip. The VG ZAB-HF ion source was the standard VG Analytical, Inc., design using a saddle field fast atom gun. In either case, samples were sputtered using an - 8-keV beam of xenon atoms with neutral beam currents equivalent to 2.0 ma supplied by an ION TECH (Model B 50) current and voltage regulator/meter. The molecular ions generated were mass selected by the first quadrupole mass analyzer, collisionally activated in the hexapole collision cell using Xe gas with a collision energy of 7 ev. Collision gas was introduced until the analyzer gas pressure was 1.0 x 10-4 Pa (normal pressure: 1.0 x 10-6 Pa). The product fragment ions formed were then mass analyzed in the second quadrupole mass analyzer. Signal adding of eight scans (3 s per scan) was performed using the multichannel analysis (MCA) software of the VG II 250 J data system. X-ray Crystallography. Crystallographic studies were performed using a Eraf-Nonius diffractometer and SDP software on a MicroVAX 2 computer. Details of specific experiments are discussed in subsequent chapters. UV-Visible Spectroscopy. The UV-visible spectra were recorded on a Hewlett-Packard 8452A Diode Array Spectrophotometer. Electrochemistry. Cyclic voltammograms were obtained, under inertatmospheric conditions, using a three-electrode system consisting of a 6.28 mm 2 Pt disk working electrode, a coiled Pt wire counter electrode, and a Ag I AgCI reference

38 10 electrode. The supporting electrolyte for the reference electrode was a LiCI saturated, 0.1 M [(n-bu) 4 N][BF 4 ] THF solution. The reference electrode was suspended within a Luggin capillary to minimize the IR drop across the electrodes. Electrochemistry was carried out with a PAR 173 Potentiostat in conjunction with a PAR 175 Programmer. Cyclic voltammograms, recorded using a HP 7040A X-Y recorder, were corrected using ferrocene versus the Ag I AgCI reference electrode (EP = V) and a standard calomel electrode (SCE) (Ep = V). Organometallic Reagents The reagents and solvents used in the preparation and reactions with these compounds are listed in Tables 2-5, and were uz.d ab supplied unless otherwise noted. The general synthesis of (hexamethylbenzene)manganese tricarbonyl hexafluorophosphate, [(tq 6 -C 6 Me 6 )Mn(CO) 3 ][PF 6 ] (1), is outlined in Scheme I.1a,ga,26 The published procedure for the synthesis of Mn(CO) 5 Br was modified to decrease reaction times and increase yields. 27 Mn(CO)sBr. Mn 2 (CO)Io (6.071 g, mmol) was placed in a 250 ml Schlenk flask and deoxygenated by first evacuating, then purging the flask with dinitrogen. The compound was then dissolved in 100 ml of CS 2 which had been evacuated and purged with nitrogen one time. Final deoxygenation was accomplished by bubbling dinitrogen through the orange-yellow solution for 15 min, which also served to cool the solution. A positive pressure of nitrogen was maintained over the solution. Bromine (1.80 ml, mmol) was then injected into the solution over a period of s. The solution color turned very dark red. The solution was carefully heated to reflux. The heat was then removed, and the solution was stirred for 2 hours. The solvent and excess bromine were removed under reduced pressure using a liquid-nitrogen-cooled solvent trap.

39 11 Scheme I. Synthesis of [(q 6 --C 6 Me 6 )Mn(CO) 3 J[PF 6 ] C 0CBrc 0c C "-ý. I I C -. B r2 "',- I O C.Mn-CO 2 OC-Mn--Br I 'C IcNc cs 2 1 o o 0 0 1) AICIla C 6 (CH 3 ) 6 Mn' 2) H0,NHPF NO c A PFO hexane The Mn(CO) 5 Br was isolated as an orange powder. Product formation was confirmed by comparison to the IR spectral data in Table 1. Yield: 97-99%. [((--C MeE)Mn(CO) 3 ][PFJ] (1). Mn(CO) 5 Br (8.425 g, mmol) and hexamethylbenzene ( g, mmol) were dissolved in 250 ml of dry hexane in a 500 ml Schlenk flask and deoxygenated by bubbling nitrogen through the solution for 15 min. The orange solution was carefully heated to reflux. AIdC 3 (10.2 g, 76.5 mmol) was added to the stirred, hot solution. The flask was then connected to a reflux condenser, then nitrogen was used to flush the flask and column for 3 min. The solution was refluxed with stirring for 0.5 h past the time required for the solution to turn colorless and a dark orange solid to form on the sides of the flask-usually about 2.5 hours. The hot hexane was decanted, and the solids were washed two times with

40 ml portions of dry hexane. The hexane solution was collected to recover unreacted hexamethylbenzene. The solid product was hydrolyzed by the rapid addition of 200 ml of ice. The mixture was stirred until all orange solid dissolves-usually 2-3 hours. The mixture was filtered until a clear yellow solution was obtained. A solution of [NH4][PF 6 ] (6.278 g, mmol) in 20 ml of H 2 0 was added to the stirred yellow filtrate, immediately precipitating compound 1. The resulting very pale yellow powder was filtered, washed with 200 ml of diethyl ether, and then dried in a desiccator overnight. Product formation was confirmed by IR and NMR spectral results, listed in Table 1. Yield: 75-85%. [(1W-C 6 Me6)Mn(CO)z(PR 3 )][PF6] (R = P(n-Bu) 3 (la), PMe 3 (1b), PPh 3 (1c), P(OMe) 3 (1d), P(OPh) 3 (le)). Compound 1 and the appropriate phosphines were used to prepare la-e by slightly modified published procedures. la,9a,26,8 The chemical reaction is depicted in eq 1. The synthesis of lc required meticulously dried Me 3 NO (the azeotropic distillation with benzene was repeated) for high yields. 1) Me 3 NO Mn + 2) PR 3 (1) 0... C C 0 CH 2 CI 2 c PR 0 PF6 0 PF6 1 la-b Typical isolation was accnmplished by adsorbing the product on silica (-50 ml) in solution, removing the solvent on a rotary-evaporator, placing the resulting silica on a prepared silica column (-50 ml), adding additional silica (- 10 ml) on top, and eluting the products with increasingly polar solvent mixtures.

41 13 Table 1. IR and IH NMR Spectral Data for Mn(CO) 5 Br and 1 Compound PCO, cm-1 a 6, ppm b Mn(CO) 5 Br 2136, 2083, 2046, , 2138, 2052, 2009, 1975 c , (s, 18 H, CH 3 ) 2060, 2001 c asolution spectra obtained in THF. b 'H NMR spectra obtained in d4-acetone. "Solution spectra obtained in dichloromethane. The solvent mixture polarity was increased by first using hexane (600 ml, 100%), then hexane:acetone mixtures (400 ml; 11:2, 5:1, 1:1 ml ratios). A yellow areneless product was eluted with the first hexane:acetone mixture (11:2). The second mixture washed the column of impurities. Finally, the product, a yellow band, was eluted with the 1:1 hexane:acetone mixture. Subsequently, the solvent was removed from the product using a rotary-evaporator until approximately 3-5 ml remained. The oil was washed, first with diethyl ether, then with petroleum ether, during which the compounds la-ld crystallized out. Compound le was recrystallized by dissolving the oil in diethyl ether (-50 ml) and adding petroleum ether (-20 ml) until the solution became cloudy, then placing the mixture in the freezer (-20 C) for 2 hours. IR and NMR spectroscopic characterization data are listed in Appendix A.