J. Am. Chem. Soc., 1998, 120(7), , DOI: /ja972816e

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J. Am. Chem. Soc., 1998, 120(7), 1430-1433, DOI:10.

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1 J. Am. Chem. Soc., 1998, 120(7), , DOI: /ja972816e Terms & Conditions Electronic Supporting Information files are available without a subscription to ACS Web Editions. The American Chemical Society holds a copyright ownership interest in any copyrightable Supporting Information. Files available from the ACS website may be downloaded for personal use only. Users are not otherwise permitted to reproduce, republish, redistribute, or sell any Supporting Information from the ACS website, either in whole or in part, in either machinereadable form or any other form without permission from the American Chemical Society. For permission to reproduce, republish and redistribute this material, requesters must process their own requests via the RightsLink permission system. Information about how to use the RightsLink permission system can be found at Copyright 1998 American Chemical Society

2 Riavtsed 2 A -Sl- Supporting Information for the manuscript: Lewis Base-Free Phenyllithium: Determination of the Solid State Structure by Synchrotron Powder Diffraction Robert E. Dinnebier, Ulrich Behrens, and Falk Olbrich* Department of Chemistry, University of Magdeburg, Universitaetsplatz 2, Magdeburg, Germany, Phone Fax falk.olbrich@chemie.unimagdeburg.de Powder X-ray diffraction experiment. For the powder X-ray diffraction experiment, the air and moisture sensitive samples were sealed in glass capillaries of 0.7 mm diameter. High resolution powder diffraction data were collected at the SUNY X3B 1 beamline at the National Synchrotron Light Source, Brookhaven National Laboratory. X-rays of wavelength (2) A were selected by a double Si(1 11) monochromator. Wavelength and zero point error have been refined using the flat plate NBS 1976 alumina standard. The diffracted beam was analyzed with a Ge(1 11) crystal and detected with a Na(TI)I scintillation counter with a pulse height discriminator in the counting chain. The incoming beam was monitored by an ionchamber for normalization for the decay of the primary beam. In this parallel beam configuration, the resolution is determined by the analyzer crystal instead of by slits. Data were taken at room temperature for 8.3 seconds at each 20 in steps of from 50 to 490.

3 2 -S2- Although 0-scans did not show serious crystallite size effects, the sample was rotated around 0 during measurement for better statistics. Low angle diffraction peaks had a FWHM of (20), significantly broader than the resolution of the spectrometer. The data reduction was performed with the program GUFI [Dinnebier, 1993]. Indexing with the ITO method [Visser, 1969] led to a monoclinic cell. The space group could be unambiguously determined as P2 1 /n by applying the extinction rules. The number of formula units per unit cell (Z) was found from estimated density. A Le-Bail fit [LeBail, Duroy, Fourquet, 1988] using the program FULLPROF [Carvajal, 1990] worked well to extract about 197 integrated intensities up to 490 in 20. These were used as input for the direct methods program SIRPOW92 [Cascarano, Favia, Giacovazzo, 1992]. None of the carbon atoms could be found by direct methods because of the insufficient peak to background ratio of the many small peaks in the higher angle region. It was therefore decided to repeat the scan and to merge the two scans together. The total counting time came out to be 16.2 seconds at each 20. Using this statistically improved data set, it was possible to detect some rough candidates for the C atoms in the electron density map. The center of gravity location of this cluster of atoms was used as a starting position for a rigid body Rietveld [Rietveld, 1969] refinement of the phenyl ring. To find a starting orientation, a least squares plane was fitted through these atoms, using an arbitrary in plane orientation of the ring. The correct location of the phenyl ring and the position of the remaining lithium atom could then be found by subsequent Rietveld refinements in combination with Difference-Fourier analysis. We used the program package GSAS [Larson, von Dreele, 1990] for the final Rietveld refinement. The peak profile function was modelled using a multiterm Simpson's rule integration of the pseudo-voigt function IThompson, Cox, Hastings, The asymmetry in the low angle region was

4 3 -S3- modelled by a lately implemented function [Finger, Cox, Jephcoat, 1994] which accounts for the asymmetry due to axial divergence, leading to a strongly improved fit and therefore better profile R-factors. A manual fit background was used in combination with a refinable 4-term cosine-series to give some flexibility back to the program. Some small humps in the background which can not be attributed to the glass capillary, suggest the presence of some amorphous fraction. In order to stabilize the refinement, we calculated the phenyl ring as an ideal six membered ring as a 'flexible' Rigid Body, allowing the refinement of the average C-C distance. This important step in the refinement process reduced the number of refinable positional parameters of non-hydrogens from 18 down to 7 (3 rotational, 3 translational and the C-C bond length). The position of the hydrogens can not be determined by powder techniques but their contribution to the profile is definitely measurable [Lightfoot, Metha, Bruce, 1993]. Since the position of the substituted hydrogen was not known from the beginning of the refinement, all 6 hydrogens have been included. Interestingly, after erasing the excessive hydrogen (H*) from the rigid body, the Li-C distance became too small. It is necessary to include H* for modelling the loan pair at C(1) into the model to get a good fitting in the refinement calculation. The high quality of the data and the lack of strong scatterers in the structure justify this model even for a refinement from powders. A refinement calculation of a modified model for the phenyl anion (distorted six membered ring because of the electron loan pair in one sp 2 orbital) did not lead to a better fitting. References: Rodriguez-Carvajal, J. Abstracts of the Satellite Meeting on Powder Diffraction of the XV Congress of the IUCr, Toulouse, Franse, 1990, p127.

5 4 -S4- Cascarano, G.; Favia, L.; Giacovazzo, C. J Appl. Crystallorgr. 1992, 25, 310. Dinnebier, R. E. GUFI: A program for measurement and evaluation ofpowder pattern, Heidelberger Geowissenschaftliche Abhandlungen 1993, 68, (Dissertation) ISBN Finger, L. W.; Cox, D. E.; Jephcoat, A. P. J Appl. Crystallorgr. 1994, 27, 892. Larson, A. C.; von Dreele, R. B. Los Alamos National Laboratory Report LAUR , updated version: May LeBail, A.; Duroy, H.; Fourquet, J. L. Mat. Res. Bull. 1988, 23, 447. Lightfood. P; Metha, M. A.; Bruce, P. G. Science 1993, 262, 883. Rietveld, H. M. J Appl. Crystallorgr. 1969, 2, 65. Thompson, P.; Cox, D. E.; Hastings, J. B. J Appl. Crystallorgr. 1987, 20, 79. Visser, J. W. J Appl. Crystallorgr. 1969, 2, 89.

6 5 Crystal Data for Deposition for the Compound Phenyllithium (LiPh) Table 1. Crystallographic data of phenyllithium (LiPh) -S5- formula C 6 H 5 Li FW (g mol- 1 ) cryst syst monoclinic space group P21/n temperature (K) 293 cell parameters: a (A) (1) b (A) 4.555(1) c (A) (1) P (o) (1) V (A 3 ) (2) Z 4 density (calcd g cm 3 ) range (0) 5.00 < 20 < steps of scan 820 = 0.01 deg. with 16.2 sec. each step FWHM 20() X (A) (2) No. of reflections in refinement 228 No. of refined parameters 30 R-values: R, RP RF Diffractometer: Huber two-circle at beamline X3B1, National Synchrotron Light Source at Brookhaven National Laboratory in US State New York

7 6 Table 2. Fractional atomic coordinates and isotropic thermal parameters (*100) for LiPh -S6- Name x Y z Ui/Ue*100 Li.5063(18) (32) (17) 17.4(7) Cl.4932(7) (10).13232(46) 4.48(32) C2.3731(5) (14).11733(32) 7.67(16) C3.3606(4).0735(14).21562(61) 7.67(16) C4.4682(7).1731(10).32889(42) 7.67(16) C5.5884(4).0829(14).34387(36) 7.67(16) C6.6009(4) (14).24559(66) 7.67(16) H2.2918(7) (20).0318(5) H3.2699(5).1416(20).2043(11) H4.4588(12).3163(11).4031(7) H5.6697(7).1581(20).4294(5) H6.6916(6) (20).2569(11) H*,.5026(12) (11).0581(7) a H* for modelling the loan pair at C1 Table 3. Bond lengths [A] and angles [0] for LiPh Atom length Atom length Atom lenght Li-Li' 2.391(28) Li-Li" 3.175(31) Li-Cl 2.242(14) Li-C1' 2.322(14) Li-Cl" 2.401(12) Li-C2" 2.514(14) Li-C3" 2.745(15) Li-C4" 2.862(14) Li-C5" 2.763(15) Li-C6" 2.534(14) C-C (18) C-H 1.05 atoms degrees atoms degrees atoms degrees C6'-Li-C (34) C6'-Li-C1' 56.79(28) C6'-Li-C" 153.8(26) Cl-Li-C' 116.8(7) Cl-Li-C" 93.8(6) C1'-Li-C1" 149.3(8) C-C-C C-C-H Li-C1-Li' 63.2(7)

8 7 -S7- Li-Cl-Li" 86.2(6) Li-Cl-C (5) Li-C1-C (5) Li-C1-H* 27.3(5) Li'-C1-Li" 149.3(8) Li'-C1-C (7) Li'-C1-C (7) Li"-C1-C2 78.1(4) Li"-C1-C6 79.0(5)

9 0 SCHRKRL I

10 0 1 -o

11 0 C(4") C (5"/) 4 I) C) CD 0~ 0" p- (1/ Li' C(4) 'C(5) I O

J. Am. Chem. Soc., 1996, 118(17), , DOI: /ja953373m

J. Am. Chem. Soc., 1996, 118(17), 4090-4093, DOI:10.1021/ja953373m Terms & Conditions Electronic Supporting Information files are available without a subscription to ACS Web Editions. The American Chemical