Origins of selectivity for the [2+2] cycloaddition of α,β-unsaturated ketones within a porous self-assembled organic framework.

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1 rigins of selectivity for the [2+2] cycloddition of α,β-unsturted ketones within porous self-ssemled orgnic frmework. Jun Yng, Mhender B. Dewl, Slvtore Profet Jr., Mrk D. Smith, Youyong Li, nd Lind S. Shimizu *. Deprtment of Chemistry nd Biochemistry, University of South Crolin, Columi, SC 29208, Mterils nd Process Simultion Center, Cliforni Institute of Technology, CA Supporting Informtion S 1

2 1 UV-Visile sornce study of host 1 nd enone guest. To test if the host 1 sors UV light in the sme rnge s the guest enones, we mesured the UV-Visile sornce of host nd guest. A comprison of the UV sornce of the is-ure mcrocycle (host 1) nd 2-cyclohexenone in DMS is shown in Figure S1. The host 1 shows only wek sornce in the nm rnge, typiclly used to fcilitte [2+2] cyclodditions. UV-Visile sornce 0.20 is-ure mcrocycle (1 mm) cyclohexenone (1 mm) A wvelength (nm) Figure S1. Comprison of UV-Visile sornce of host 1 in DMS versus 2-cyclohexenone in DMS. 2 Chrcteriztion of [2+2] cycloddition of 2-cyclohexenone 5 in the presence of host 1. For enones, the intersystem crossing is efficient nd [2+2] cycloddition of enones ws elieved to occur through triplet excited stte nd the exo hd-to-hed nd exo hed-to-til products were the mjor products. 1 We lso chrcterized [2+2] cycloddition products of other enones sed on literture reports, 1 NMR, moleculr weight nd the order of elution in GC-MS. 2 Scheme S1. Photodimeriztion of 2-cyclohexenone 5 in the presence nd sence of host 1. hv two minor products 5 without host 1: with host 1: 5 5 mjor pproducts exo 35% 49% 16% 96% 3% 1% [2+2] cycloddition of net liquid of 2-cyclohexenone 5 (control) nd 2-cyclohexenone in the presence of host 1 were crried out using novi medium-pressure 450 W mercury rc lmp cooled in orosilicte immersion well, nd the entire pprtus ws plced in UV shielded nd refrigerted rection chmer. After the irrdition, the control ws dissolved in CDCl 3. A smll mount of the solution ws tken nd chrcterized y GC-MS. There re 4 peks for dimeric products, displying moleculr weight 192. No strting mteril ws oserved. The reminder of the solution ws purified vi column chromtogrphy with EtAc/exne (1:4) nd 3 products were isolted. These three products were further chrcterized y 1 NMR, 13 C NMR nd GC-MS. The S 2

3 host 1 2-cyclohexenone crystls were shken with 1 ml of CDCl 3 for 1 h. Anlysis of the CDCl 3 filtrte y GC-MS showed tht the exo T product 5 ws the mjor product. The structure of stndrd T dimer 5 ws confirmed s cis-nti-cis-tricyclo ( )dodecne-3,9-dione y X-ry crystllogrphy. 3 A smll smple of the complex ws lso dissolved directly in d6-dms for comprison. The T dimer 5 hd shorter retention time y GC-MS (Figure S3) thn exo product 5 ecuse of their difference on the dipole moment. The product 5 ws reported to e the mjor product when 2-cyclohexenone 5 is irrdited in polr solvent or with inorgnic zeolites. 4 photolysis product with host Figure S2. 1 NMR of photolysis product of 2-cyclohexenone 5 with the presence of host 1 nd two isolted mjor dimers from the control. 5 cis-nti-cis-tricyclo( )dodecne-3,9-dione: ple yellow solid; 1 NMR (300 Mz, CDCl 3 ): δ 1.67, (m, 2), , (m, 6), 2.24, (m, 2), 2.40, (m, 2), 2.64, (t, J = 7.2, 7.5 z, 2), 3.02 ppm, (m, 2); 13 C NMR (75 M z, CDCl 3 ): δ 21.7, 27.3, 38.6, 40.4, 47.8, 213.4; MS (m/z) 192 (42) [M + ], 68 (100), 96 (35), 150 (34); RMS clcd for C , found Photolysis product from host photolysis of liquid 2-cyclohexenone control 5 dimer 5 isolted y column chromtogrphy Figure S3. GC-MS spectr of photolysis product of 2-cyclohexenone 5 with the presence of host 1 nd isolted mjor dimer 5 from the control. S 3

4 3 Chrcteriztion of [2+2] cycloddition rection of 3-methyl-2-cyclopentenone 6 in the presence of host 1. [2+2] cycloddition of 3-methyl-2-cyclopentenone in the presence of host 1 ws crried out using novi medium-pressure 450 W mercury rc lmp cooled in orosilicte immersion well, nd the entire pprtus ws plced in UV shielded nd refrigerted rection chmer. After the irrdition, the complex, crystls were either dissolved directly into d 6 -DMS or shken with 1 ml of CDCl 3 for 1 h. Anlysis of the CDCl 3 filtrte y GC-MS showed tht the exo hed-to-til product ws the only mjor product. A smll mount of strting enone (20%) ws lso oserved. Scheme S2. Photodimeriztion of 3-methyl-2-cyclopenenone 6 in the presence nd sence of host 1. 6 hv 24 h 6 6 6c 6d 6e 6f without host 1: (30% conversion) with host 1: (80% conversion) mjor products 27% 52% 98% 2.0% 4 minor products 13% <1% : 4 minor products were cited from literture ,6-dimethyl-cis-nti-cis-tricyclo[ ,6 ]decne-3,8-dione: 1 NMR (300 Mz, CDCl 3 ): δ 1.16, (m, 6), , (m, 2), , (m, 2), 2.34, (s, 2), ppm, (m, 4); 13 C NMR (75 Mz, CDCl 3 ): δ 22.8, 37.4, 39.3, 41.0, 59.7, 219.3; MS (m/z) 192 (15) [M + ], 96 (100), 97 (85), 81 (25), 108 (20). C 3 C 3 3 C Figure S4. 1 NMR of the host 1 3-methyl-2-cyclopentenone 6 inclusion complex ) efore UV irrdition nd ) fter 24 hours of UV irrdition. S 4

5 C 3 3 C Figure S5. GC-MS spectr of cycloddition products of 3-methyl-2-cyclopentenone 6 from the host 1 complex fter UV irrdition nd extrction. X-ry crystl structure of 6 1,6-dimethyl-cis-nti-cis-tricyclo[ ,6 ]decne-3,8-dione: X-ry diffrction intensity dt from colorless prism crystl were mesured t 150(1) K using Bruker SMART APEX diffrctometer (Mo Kα rdition, λ = Å). 6 Severl crystls were surveyed, ll of which were found to e twinned. The crystl selected for dt collection ws composed of two domins. Identifiction of the twinning nd derivtion of the twin lw which trnsforms the indices of one domin into those of the other ws performed with the Bruker progrm Cell_Now. 6 The twin lw is which corresponds to 180 rottion out the reciprocl [001] xis. Integrtion of the twinned rw dt frmes ws performed with SAINT+. 6 Reflection files for structure solution (SELX KLF 4 formt) nd twin refinement (SELX KLF 5 formt) were creted with TWINABS. 6 Finl unit cell prmeters were determined y lest-squres refinement of 2043 strong reflections from the mjor domin. Direct methods structure solution, difference Fourier clcultions nd full-mtrix lest-squres refinement ginst F 2 were performed with SELXTL. 7 The mjor twin frction refined to 0.730(1). The compound crystllizes in the triclinic system. The spce group P 1 ws confirmed y the successful solution nd refinement of the dt. The symmetric unit consists of one complete molecule. All non-hydrogen toms were refined with nisotropic displcement prmeters. ydrogen toms were locted in difference mps efore eing plced in geometriclly idelized positions nd included s riding toms with refined isotropic displcement prmeters S 5

6 Tle S1. Crystl dt nd structure refinement for 1,6-dimethyl-cis-nti-cis-tricyclo[ ,6 ]- decne-3,8-dione 6. Identifiction code Empiricl formul 6 C Formul weight Temperture Wvelength Crystl system Spce group 150(1) K Å Triclinic P 1 Unit cell dimensions = (12) Å α= (3). = (12) Å β= (3). c = (2) Å γ = (3). Volume (16) Å 3 Z 2 Density (clculted) Mg/m 3 Asorption coefficient mm -1 F(000) 208 Crystl size 0.32 x 0.14 x 0.10 mm 3 Thet rnge for dt collection 1.66 to Index rnges -7<=h<=7, -7<=k<=7, 0<=l<=14 Reflections collected 1899 Independent reflections 1899 [R(int) = ] Completeness to thet = % Asorption correction None Refinement method Full-mtrix lest-squres on F 2 Dt / restrints / prmeters 1899 / 0 / 146 Goodness-of-fit on F Finl R indices [I>2sigm(I)] R1 = , wr2 = R indices (ll dt) R1 = , wr2 = Lrgest diff. pek nd hole nd e.å -3 S 6

7 4 Chrcteriztion of [2+2] cycloddition rections of 2-methyl-2-cyclopentenone 7 in the presence of host 1. [2+2] cycloddition of 2-methyl-2-cyclopentenone in the presence of host 1 ws crried out using novi medium-pressure 450 W mercury rc lmp cooled in orosilicte immersion well, nd the entire pprtus ws plced in UV shielded nd refrigerted rection chmer. After the irrdition, the complex, crystls were either dissolved directly into d 6 -DMS or shken with 1 ml of CDCl 3 for 1 h. The CDCl 3 filtrte ws used for GC-MS. The nlysis shown tht the [2+2] cycloddition of 2-methyl-2-cyclopentenone 7 in the presence of host 1 resulted in the mixture of 80% of exo T product 7 nd 20% of exo product 7. Scheme S3. Photodimeriztion of 2-methyl-2-cyclopentenone 7 in the presence nd sence of host 1. hv 7 24 h 7 7 without host 1: (27% conversion) with host 1: (95% conversion) 28% 72% 80% 20% 7 2,7-dimethyl-cis-nti-cis-tricyclo[ ,6 ]decne-3,8-dione: 1 NMR (300 Mz, CDCl 3 ): δ 1.26, (m, 6), , (m, 4), , (m, 4), ppm, (m, 2); MS (m/z) 192 (25) [M + ], 97 (100), 96 (65), 164 (25), 107 (20). 7 1,2-dimethyl-cis-nti-cis-tricyclo[ ,6 ]decne-3,10-dione: 1 NMR (300 Mz, CDCl 3 ): δ 1.12, (m, 6), , (m, 4), , (m, 4), ppm, (m, 2); MS (m/z) 192 (88) [M + ], 96 (100), 97 (58), 68 (44), 107 (25). Figure S6. 1 NMR (d6-dms) of the host 1 2-methyl-2-cyclopentenone 7 inclusion complex ) efore UV irrdition nd ) fter 24 hours of UV irrdition. S 7

8 Figure S7. GC-MS spectr of cycloddition products of 2-methyl-2-cyclopentenone 7 from the host 1 complex fter UV irrdition nd extrction. X-ry crystl structure of 7 2,7-dimethyl-cis-nti-cis-tricyclo[ ,6 ]decne-3,8-dione: X-ry diffrction intensity dt from colorless plte crystl were mesured t 150(1) K using Bruker SMART APEX diffrctometer (Mo Kα rdition, λ = Å). 4 Rw re detector dt frme integrtion ws performed with SAINT+. 6 Finl unit cell prmeters were determined y lest-squres refinement of 2964 strong reflections from the dt set. Direct methods structure solution, difference Fourier clcultions nd full-mtrix lest-squres refinement ginst F 2 were performed with SELXTL. 7 The compound crystllizes in the spce group P2 1 /n s determined uniquely y the pttern of systemtic sences in the intensity dt. The symmetric unit consists of hlf of one molecule locted on crystllogrphic inversion center. All non-hydrogen toms were refined with nisotropic displcement prmeters. ydrogen toms were locted in difference mps efore eing plced in geometriclly idelized positions nd included s riding toms with refined isotropic displcement prmeters. S 8

9 Tle S2. Crystl dt nd structure refinement for 2,7-dimethyl-cis-nti-cis-tricyclo[ ,6 ]- decne-3,8-dione 7. Identifiction code Empiricl formul 7 C Formul weight Temperture Wvelength Crystl system 150(1) K Å Monoclinic Spce group P2 1 /n Unit cell dimensions = (7) Å α= 90. = (7) Å β= (2). c = (11) Å γ = 90. Volume (9) Å 3 Z 2 Density (clculted) Mg/m 3 Asorption coefficient mm -1 F(000) 208 Crystl size 0.48 x 0.30 x 0.12 mm 3 Thet rnge for dt collection 3.22 to Index rnges -8<=h<=8, -7<=k<=7, -13<=l<=13 Reflections collected 4987 Independent reflections 867 [R(int) = ] Completeness to thet = % Asorption correction None Refinement method Full-mtrix lest-squres on F 2 Dt / restrints / prmeters 867 / 0 / 73 Goodness-of-fit on F Finl R indices [I>2sigm(I)] R1 = , wr2 = R indices (ll dt) R1 = , wr2 = Lrgest diff. pek nd hole nd e.å -3 S 9

10 5 Chrcteriztion of [2+2] cycloddition rections of smll enones in the presence of host 1.. ost 1 ws treted with crylic cid 2 vpor for 24 hours forming host 1 crylic cid complex (3:2 stoichiometry). The host guest complex ws irrdited under UV lmp for 24 h nd 1 NMR showed only peks corresponding to host 1 nd crylic cid 2, indicting tht no rection occurred. Figure S8. 1 NMR of the host 1 crylic cid inclusion complex ) efore UV irrdition nd ) fter 24 hours of UV irrdition.. ost 1 ws treted with methylvinyl ketone for 24 hours forming host 1 MVK complex (5:2 stoichiometry). The host guest complex ws irrdited under UV lmp for 24 hours nd 1 NMR showed only peks corresponding to host 1 nd MVK 3, indicting tht no rection occurred. Figure S9. 1 NMR of the host 1 methylvinyl ketone inclusion complex ) efore UV irrdition nd ) fter 24 hours of UV irrdition. S 10

11 c. ost 1 ws treted with 2-cyclopentenone 4 vpor for 7 dys forming host 1 2-cyclopetenone complex (1:2 stoichiometry). The host guest complex ws irrdited under UV lmp for 24 hours nd 1 NMR showed only peks corresponding to host 1 nd 2-cyclopentenone 4, indicting tht no rection occurred. Figure S10. 1 NMR of the host 1 2-cyclopentenone inclusion complex ) efore UV irrdition nd ) fter 24 hours of UV irrdition. 6 Chrcteriztion of [2+2] cycloddition rections of lrge enones in the presence of host 1.. Mesityl oxide 8 hs the clculted moleculr volume of 107 Å 3. ost 1 ws treted with mesityl oxide vpor for 24 hours forming host 1 mesityl oxide complex (5:1 stoichiometry). The host guest complex ws irrdited under UV lmp for 24 hours nd 1 NMR showed only peks corresponding to host 1 nd mesityl oxide 8, indicting tht no rection occurred. Figure S11. 1 NMR of the host 1 mesityl oxide inclusion complex ) efore UV irrdition nd ) fter 24 hours of UV irrdition. S 11

12 . 2,3-dimethyl-2-cyclopentenone 9 hs the clculted moleculr volume of 114 Å 3. ost 1 ws treted with 2,3-dimethyl-2-cyclopentenone 9 for 7 dys forming host 1 2,3-dimethyl-2-cyclopentenone complex (2:3 stoichiometry). The host guest complex ws irrdited under UV lmp for 24 hours nd 1 NMR showed complex mixture of isomers ws otined. Further GC-MS nlysis showed tht the mixture contined 8 isomers with the expected moleculr weight (220 g/mol). Figure S12. 1 NMR of the host 1 2,3-dimethyl-2-cyclopetenone inclusion complex ) efore UV irrdition nd ) fter 24 hours of UV irrdition. products extrcted from host 1 Control Figure S13. GC-MS spectr of cycloddition products of 2,3-dimethyl-2-cyclopentenone 9 from the host 1 complex fter UV irrdition nd extrction. 2 S 12

13 7 hrcteriztion of [2+2] cycloddition rections of lrge enones with the presence of host 1, which were not le to e ound with host 1.. TGA study of host 1 fter soking in 3-methyl-2-cyclohexenone 6. Lrge size cyclic enones were not ound y vpor tretment of the host 1. We tested if the host would sor these enones from the liquid stte. For exmple host 1 ws immersed in 3-methyl-2-cyclohexenone 6 liquid for 2 hours. After filtrtion nd ir dry for 5 minutes, the resulted solid were used for TGA study. TGA desorption curve showed tht the weight loss ws oserved immeditely t room temperture nd ws dependent on the ir drying time, indicting tht no stle inclusion complex ws formed. This result suggested tht the enone molecules re coted on the outer surfce of the microporous crystls insted of filled inside the cvities Weight loss (%) Temperture ( C) Figure S14. TGA desorption of host 1 3-methyl-2-cyclohexenone 6 mixture.. 3-methyl-2-cyclohexenone 10 hs clculted moleculr volume s 114 Å 3 nd ws not le to form host guest complex y vpor tretment with the empty host. The crystlline host 1 ws soked in 3-methyl-2-cyclohexenone liquid for 2 h then recovered y filtrtion nd ir dried. The host guest mixture ws irrdited under UV for 24 hours. After irrdition, 1 NMR of the mixture showed mixture of isomers hd een otined. Further GC-MS nlysis indicted tht the percentge of ech isomer is similr to the control. 8 Figure S15. 1 NMR of the host 1 3-methyl-2-cyclohexenone mixture 10 ) efore UV irrdition nd ) fter 24 hours of UV irrdition. S 13

14 Figure S16. GC-MS spectr of cycloddition products of 3-methyl-2-cyclohexenone 10 from the host 1 3-methyl-2-cyclohexenone mixture fter UV irrdition nd extrction. c. 4,4-dimethyl-2-cyclohexenone 11 hs clculted moleculr volume s 130 Å 3 nd ws not le to form host guest complex y vpor tretment with the empty host. The crystlline host 1 ws soked in 4,4-dimethyl-2-cyclohexenone liquid for 2 h then recovered y filtrtion nd ir dried. The host guest mixture ws irrdited under UV for 24 hours. After irrdition, 1 NMR of the mixture showed mixture of isomers hd een otined. Further GC-MS nlysis indicted tht the percentge of ech isomer is similr to the control. 9 Figure S17. 1 NMR of the host 1 4,4-dimethyl-2-cyclohexenone 11 mixture ) efore UV irrdition nd ) fter 24 hours of UV irrdition. S 14

15 Figure S18. GC-MS spectr of cycloddition products of 4,4-dimethyl-2-cyclohexenone 11 from the host 1 4,4-dimethyl-2-cyclohexenone mixture fter UV irrdition nd extrction. d. 3,5-dimethyl-2-cyclohexenone 12 hs clculted moleculr volume s 131 Å 3 nd ws not le to form host guest complex y vpor tretment with the empty host. The crystlline host 1 ws soked in 3,5-dimethyl-2-cyclohexenone liquid for 2 hours then recovered y filtrtion nd ir dried. The host guest mixture ws irrdited under UV for 24 hours. After irrdition, 1 NMR of the mixture showed mixture of isomers hd een otined. Further GC-MS nlysis indicted tht the percentge of ech isomer is similr to the control. 8,10 Figure S19. 1 NMR of the host 1 3,5-dimethyl-2-cyclohexenone 12 mixture ) efore UV irrdition nd ) fter 24 hours of UV irrdition. S 15

16 Figure S20. GC-MS spectr of cycloddition products of 3,5-dimethyl-2-cyclohexenone 12 from the host 1 3,5-dimethyl-2-cyclohexenone mixture fter UV irrdition nd extrction. 8 Tle of indexes nd d spcing of powder X-ry diffrction of the host 1 enone guest complexes efore [2+2] cycloddition rections. S 16

17 9 Powder X-ry diffrction of the host 1 enone guest complexes fter [2+2] cycloddition rections. After irrdition of host 1 enone inclusion complexes, the resulted solids were investigted y powder X-ry diffrction. The irrdited host 1 2-cyclohexenone complex showed well defined powder ptterns, which re distinct from the complex efore irrdition, indictive of well ordered nd highly crystlline form. Figure S21. Powder X-ry diffrction of host 1 2-cyclohexenone complex efore rection nd fter 24 hours of UV irrdition. The irrdited complex host 1 3-methyl-2-cyclopentenone showed well defined powder ptterns indictive of well ordered nd highly crystlline form. Figure S22. Powder X-ry diffrction of host 1 3-methyl-2-cyclopentenone complex efore rection nd fter 24 hours of UV irrdition. S 17

18 10 he reltionship etween TGA dt nd physicl properties of guest molecules. We compred the TGA dt (temperture t hlf guest is lost, T 1/2 ) with some physicl properties of the guest molecules y plotting T 1/2 vs dipole moment of guest molecule (Figure S23) nd T 1/2 vs oiling point of guest molecule (Figure S23). T 1/2 ppered to e loosely correlted with the dipole moments of the guest molecules. No correltion ws pprent etween T 1/2 nd the oiling points of the enone guests. These results suggest tht the dipole-dipole interction is n importnt driving force for guest inding. Tle S3. Correltion etween T 1/2 with guest dipole moment nd guest oiling point T 1/2 vs guest dipole moment T 1/2 vs guest oiling point T1/2 ( o C) dipole moment of enones (D) 5 T1/2 ( o C) Boiling point ( o C) Figure S23. ) Plot of T 1/2 versus guest dipole moment; ) Plot of T 1/2 versus guest oiling point. S 18

19 References: 1. () Eton, P. E. J. Am. Chem. Soc. 1961, 84, () Wgner, P. J.; Bucheck, D. J. J. Am. Chem. Soc. 1969, 91, (c) Lem, G.; Kprinidis, N. A.; Schuster, D. I. J. Am. Chem. Soc. 1993, 115, (d) Cecil, J. C.; Dyer, C. W.; Fleming, S. A.; Jessop, T. C. Anl. Sci. 1999, 15, Anklm, E. K.; Wilfried, A. Mrgreth, P. Tetrhedron Lett. 1983, 24, Tylor, A.; Eisenrun, E. J.; Browne, C. E.; olt, E. M. Act Cryst. 1997, C53, () Lm, E. Y. Y.; Donld, V.; mmond, G. S. J. Am. Chem. Soc. 1967, 89, () Wgner, P. J.; Dvid, J. B. J. Am. Chem. Soc. 1969, 91, (c) Lem, G.; Nikols, K.A.; Schuster, D. I.; Ghtli, N. D.; Turro, N. J. J. Am. Chem. Soc. 1993, 115, (d) Mdhvn, D.; Pitchumni, K. Photochem. Photoiol. Sci , () Mrk, G.; Mttheus,.; Mrk, F.; Leitich, J.; enneerg, D.; Schomurg, G.; Von Wilucki, I.; Polnsky,. E. Montsh. Chem. 1971, 102, () Reinfried, R.; Bellus, D.; Schffner, K. elvetic Chimic Act 1971, 54, (c) Yvon, K. Act Cryst. 1974, B30, (d) Ro, V. P.; Fech, J. J. Photochem. Photoiol. A: Chem. 1992, 67, SMART Version nd SAINT+ Version Bruker Anlyticl X-ry Systems, Inc., Mdison, Wisconsin, USA, Sheldrick, G. M. SELXTL Version 6.14; Bruker Anlyticl X-ry Systems, Inc., Mdison, Wisconsin, USA, Ziffer, ; Fles,. M.; Milne, G. W. A.; Field, F.. J. Am. Chem. Soc. 1970, 92, () 9. Schuster, D. I.; Greenerg, M. M.; Nunez, I. M.; Tucker, P. C. J. rg. Chem. 1983, 48, Fox, M. A.; Crdon, R.; Rnde, A. C. J. rg. Chem. 1985, 50, ) Bolton, K.; Lister, D. G. nd Sheridn, J., J. Chem. Soc. Frdy-II. Mol. Chem. Phy., 1974, 70, ) Chdwick, D.; Legon A. C. nd Millen, D. J., J. Chem. Soc. Frdy-II. Mol. Chem. Phy., 1979, 75, c) Pite, D. nd Fvini, G., J. Chem. Soc. Perkin-II. Phy. rg. Chem., 1972, 2, ) Lide, D. R., ndook of Chemistry nd Physics 83rd Ed , CRCpress. Pg 9-50; ) Pelez, F. J.; Lopez, J. C.; Alonso, J. L., J. Mol. Struct., 1987, 159, ) Bock, E. nd Dojck, E. F., Cn. J. Chem., 1967, 45, ; ) Foster, P. D.; Ro, V. M. nd Curl, Jr. R. F., J. Chem. Phy., 1965, 43, S 19

Construction of right-handed-, left-handed- and racemic helical. coordination polymers. Enantioselective recognition via chiral.

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