Organometallics 1982,1, 998-1003
998
The spectra were usually acquired from concentrated solutions in pure C&,. Where photolyses to silaethylenes were involved, NMR tubes were sealed under an argon atmosphere. '9spectra were acquired on a Varian CFT 20,a Bruker WM-250instrument, or more usually on the Bruker WH-400spectrometer operating in the FT mode at a frequency of 100.62 MHz, operated by the Southwestern Ontario NMR Centre located at the University of Guelph, Guelph, Ontario. The spectra were run with level decoupling with the decoupler set at low power between acquisitions in order to obtain proton-'% NOE. Moderately long delays (-30 s) were allowed between pulses, especially when the carbonylcarbon was being studied. C6D6was used as internal lock and internal chemical shift callibration for 13C. %Si spectra were obtained on the same Bruker WH-400 spectrometer operating at a frequency of 79.495 MHz in the FT mode. The chemical shifts are reported relative to the silicon resonance of Me4Si, used as an external reference. All of the spectra were obtained by using a gated decoupling sequence in which the protons were broad-band decoupled only during acquisition of the silicon free induction decay. This results in the complete suppression of the nuclear Overhauser enhancement. In the cases where no relaxation agent was added, spectra were accumulated by using approximately a 30° pulse width and ap(14)Brook, A. G.;Kallury, R. K.M.R.; Poon, Y. C., Organometallics, preceding paper in this issue.
proximately a 1-min relaxation delay between pulses. In some of the spectra Gaussian multiplication was employed to provide resolution enhancement.
Acknowledgment. We are grateful to Drs. R. K. M. R. Kallury, B. Behnam, L. Yau, and Y.-M. Chang for supplying some of the compounds, to Dr. R. E. Lenkinski and Bruce MacDonald of the SW Regional NMR Centre for assistance and advice, and to Mrs. Brigitte Gutekunst for technical assistance. This research was supported financially by the Natural Sciences and Engineering Research Council of Canada. Registry No.(Me3Si),SiCOCMe3,69397-47-3; (Me3Si),SiCOCE0, 72214-49-4;(Me3Si)3SiCO(1-methyl-l-cyclohexyl), 81671-42-3; (Me3Si)3SiCO(1-bicyclo[2.2.2]octyl),81671-43-4;(Me3Si)3SiCO(1adamantyl), 72189-53-8; (Me3Si)&COPh, 60154-95-2; (Me3Si)3SiCOC6H,-p-OMe, 81671-44-5; (Me3Si)3SiCOC6H1-o-OMe, 81671-45-6;(Me3Si),SiCOCF3, 81671-46-7;(Me3Si)3SiCOC6F5, 81671-47-8;(Me3Si)3SiCOOH,70096-33-2;(Me3Si)3SiCOOSiPh3, 81671-48-9;(Me3Si),SiSiMe3,4098-98-0;Ph3SiCOMe, 4916-42-1; Me3SiCOMe, 13411-48-8;Me3SiCOPh, 5908-41-8;Et3SiCOPh, 63935-93-3; Ph3SiCOPh, 1171-49-9;(Me3Si)zSi=C(OSiMe3)(CMe3), 81671-49-0;(Me3Si),Si=C(OSiMe3)(CEO), 81671-50-3; (Me,Si)#i= C(OSiMe,)(l-methyl-1-cyclohexyl), 81671-51-4;(Me3Si)zSi=C(OSiMeJ(l-adamantyl),72189-54-9.
Crystal and Molecular Structure of Cyclopentadienylerbium Dichloride Tris(tetrahydrofuranate), (C,H,)ErCI,(THF), Cynthia S. Day," Victor W. Day,*1b12 Richard D. Ernsf,*lc and Sarah H. Vollmer'b Departments of Chemistry, University of Utah, Salt Lake City, Utah 84 1 12, and The University of Nebraska, Lincoln, Nebraska 68588, and Crystalytics Company, Lincoln, Nebraska 6850 1 Received November 13, 198 1
The nature of the (C5H5)LnC1,(THF),compounds has been investigated by an X-ray structural determination of the Ln = Er complex. The compound crystallizes in the monoclinic space group ml/n with four molecules in a unit cell of dimensions a = 7.822 (2)A, b = 17.096 (4)A, c = 15.162 (3)A, and /3 = 95.80 (2)". Least-squares refinement of the 208 variables led to a value for the conventional R index (on F)of 0.029 for 4207 independent reflections having 2 8 ~ ~3u(I). flections having 20MoKn (20) Cruikshank, D. W. J. In 'Crystallographic Computing";Ahmed, F. R., Ed.; Munksgaard Copenhagen, 1970; pp 187-196.
lo00 Organometallics, Vol. 1, No. 7, 1982
atom
Day et al.
Table I. Positional and Thermal Parameters for Nonhydrogen Atoms in Crystalline (Q~-C,H,)E~CI,(OC,H,)~~ fractional coordinates anisotropic parameters,CA 3
io4% 104~ 104% Bll Bzz B13 BIZ B13 B23 558.2 (2) 503.0 (1) 2657.3 (1) 2.75 (1) 3.45 (1) 2.92 (1) -0.17 (1) 0.15 (1) 0.07 (1) 7.11 (7j 4.16 (5 j -0.71 ( 5 j 0.97 (4j -2002(11 178 (1) 3577 (1) 3.69 (4) 0.02 (5j 1373 (1j 4-61 ( 5 j 6.42 (7) 4.28 (5) -0.06 (5) 1.47 (4) 297 ( i j 0.29 (5) 2517 i2j 4.7 (1) 4.1 (1) 3.4 (1) -542 (2) 3386 (2) 0.0 (1) -0.0 (1) 1.1(1) 2057 (4) 3.7 (1) 5.0 (2) 5.6 ( 2 ) -0.6 (1) -1.6 (1) -785 (4) 1878 (3) 0.2 (1) -632 (2) 3.8 (1) 5.7 (2) 3.6 (1) 1.0 (1) -0.0 (1) 0.5 (1) -1518 (4) 1080 (2) 1614 (2) 4115 (4) 6.2 (3) 1.3 (3) 1.3 (2) 1.9 ( 2 ) -987 ( 4 ) 6.8 (3) 4.8 (3) 1498 (9) 8.8 (5) 3.2 (4) 4.1 (4) 4421 (5) 9.8 (5) 7.4 (4) 1.6 (4) 2929 (12) -1506 (5) 4.1 (5) 11.3 (6) 10.0 (5) 3986 (6) 6.0 (4) 2.7 (4) -0.2 (4) 4405 (10) -1250 (6) 3263 (6) 3.5 (2) 11.2 (5) 0.7 (3) 3.9 (4) 3812 (8) -769 (5) 1.3 (2) 8.0 (4) 6.2 (3) 1684 (5) 7.6 (4) 8.0 (4) 0.1 (3) -0.1 (3) -3.2 (3) 70 (10) -1335 (4) 7.5 (4) -1.4 (3) -0.4 (4) -1.3 (3) 5.7 (3) -1181 (12) -1874 (4) 1237 (5) 9.6 (5) 6.8 (5) 1094 (9) 10.5 (6) 17.4 (9) -3.0 (4) -6.7 (6) -1.0 (5) -2712 (14) -1441 (6) 1585 (8) 5.0 (3) 9.8 (5) 14.9 (8) -1.3 (3) -1.8 (4) -5.4 (5) -2540 (10) -735 (6) 7.6 (4) 13.3 (7) 4.1 (3) 4.7 (4) 1.1(2) 2.4 (3) -1268 (10) 703 (4) 1234 (6) 16.6 (8) 2.6 (4) 302 (5) 10.7 (6) 4.8 (3) 7.2 (6) 0.1 (3) -2835 (12) 1598 (7) 1019 ( 6 ) 7.4 (4) 10.2 (5) 8.0 (4) 4.7 (4) 1.1(3) 2.7 (4) -3746 (10) 1889 (5) 7.3 (3) 1805 (4) 4.7 (2) 5.5 (3) 2.4 (2) 0.4 (2) 0.5 (3) -3129 (7) 1429 (4) 2987 ( 5 ) 6.9 (3) 3.4 (2) 6.7 (3) -0.7 (2) -0.1 (3) -0.3 (2) 939 (9) 2033 (3) 2795 (5) 1.6 (3) -0.6 (2) 6.7 (3) 4.9 (3) 2537 (9) 1773 (4) 6.9 (3) -2.3 (2) 5.9 (3) 4.5 (2) 3185 (8) 1292 (4) 3487 (5) 8.2 (4) -1.0 (2) -0.9 (3) -1.8 (3) 1247 (4) 4097 (4) 5.0 (3) 4.6 (2) -1.0 (2) -0.9 (2) -0.9 (2) 7.2 (3) 1955 (9) 4.9 (3) 3780 (4) 5.8 (3) -0.5 (2) 0.7 (2) -1.6 ( 2 ) 569 (8) 1705 (3) 6.0 (3) Numbers in parentheses are the estimated standard deviation for the last significant digit. Atoms are labeled in agreement with Figure 1. The form of the anisotropic temperature factor is exp[-0.25(B,lhza*z + B,,k2b*z + B,312c*2 + 2Blzhka*b* + 2B13hZa*c*+ 2B,,klb*c*)]. typeb
Er c1,
The location of the erbium atom was determined from a Patterson synthesis. Following refinement of the erbium atom (R?l= 0.238), all remaining nonhydrogen atoms were located on a difference Fourier map. Unit-weighted (w = 1) isotropic least-squares refinement for the nonhydrogen atoms converged to RlZ1= 0.051 and R?' = 0.054 for 2036 independent reflections having 20MoKn
