solution was filtered and added gradually to a filtrated brown solution of 2
(0.298 g, 1.29 mmol) in 7–8 mL of toluene. The resulting solution rapidly
turned green and crystals of 3 appeared on the bottom and walls of the
vessel. After 24 h the solution was decanted. Subsequent washing of the
dark green crystals with cold toluene and drying in vacuum gave 0.485 g
(92%) of 3, mp 220–222uC (dec.) under Ar.
} Data for 3: elemental analysis calcd for C24H24Ti2: C, 70.62; H, 5.93.
Found: C, 70.14; H 5.88%. 1H NMR (C6D6, 297 K): d 3.97 (br., 4H, CH2);
5.18 (s, 20H, Cp). 13C{1H} NMR (C6D6, 297 K): d 85.5 (CH2); 108.5 (Cp);
153.4 (CLC). MS (70 eV, m/z): 408 [M]1, 406 [M 2 2H]1, 352 [M 2
C4H8]1, 178 [Cp2Ti]1.
, X-Ray crystal structure analysis of 3: STOE-IPDS diffractometer,
graphite monochromated MoKa radiation, solution of the structure by
direct methods (SHELXS-8611), refinement with full-matrix least-squares
techniques against F2 (SHELXL-9312). Crystal data: monoclinic, space
Scheme 3 Formation of m-butadiyne complexes (D).
We have studied the structure and bonding of these molecules
using Density Functional Theory calculations (B3LYP/
LANL2DZ).9 The calculated geometrical parameters are in close
agreement with the experimental structure. The bonding in 3 is
best described by treating the bridging ligand as formally
[H2CCCCH2](24) species, making Ti(14). The C1–C(1A) p bond
perpendicular to the TiC4Ti plane does not interact substantially
with the metals. The remaining eight valence electrons of the
[H2CCCCH2](24) ligand occupy four in-plane delocalized orbitals
resulting from the interaction with the Cp2Ti fragment orbitals.
The bonding here is very similar to that in the m-trans-butadiyne
complex [Cp2Ti(HCCCCH)TiCp2] (type D) except that 3 has an
ethylenic p bond in place of the trans-butadiene of the butadiyne
complex.10 A C2v isomer of 3 derived directly from the com-
plexation of the middle C1–C(1A) bond of 2 is calculated to be
higher in energy by 9.00 kcal mol21. Experimental and theoretical
studies on the details of this species, its conversion to 3, and further
transformations of 3 are currently in progress.
˚
group P21/n, a ~ 8.687(2), b ~ 7.887(2), c ~ 13.353(3) A; b ~ 90.17(3)u;
V ~ 914.9(4) A , Z ~ 2, Dc ~ 1.482 g cm23; 2621 reflections measured,
3
˚
1429 were independent of symmetry and 1221 were observed [I w 2s(I)],
R1 ~ 0.036, wR2(all data) ~ 0.096, 126 parameters. CCDC 239591. See
.cif or other electronic format.
1 A. Maercker and A. Groos, Angew. Chem., 1996, 108, 216, Angew.
Chem., Int. Ed. Engl., 1996, 35, 210.
2 N. Suzuki, M. Nishiura and Y. Wakatsuki, Science, 2002, 295, 660.
3 N. Suzuki, N. Ahihara, H. Takahara, T. Watanabe, M. Iwasaki,
M. Saburi, D. Hashizume and T. Chihara, J. Am. Chem. Soc., 2004, 126,
60.
4 U. Rosenthal, P.-M. Pellny, F. G. Kirchbauer and V. V. Burlakov, Acc.
Chem. Res., 2000, 33, 119.
5 (a) U. Rosenthal and V. V. Burlakov, in Titanium and Zirconium in
Organic Synthesis, ed. I. Marek, Wiley-VCH, Weinheim, 2002, p. 355;
(b) U. Rosenthal, V. V. Burlakov, P. Arndt, W. Baumann and
A. Spannenberg, Organometallics, 2003, 22, 884.
This work was supported by the SPP 1118 of the Deutsche
Forschungsgemeinschaft (RO 1269/5–1) and the Russian Founda-
tion for Basic Research (Project code 02-03-32589).
6 (a) K. C. Lam and Z. Lin, Organometallics, 2003, 22, 3466;
(b) E. D. Jemmis, A. K. Phukan, H. Jiao and U. Rosenthal,
Organometallics, 2003, 22, 4958; (c) U. Rosenthal, Angew. Chem.,
2004, 116, 3972, Angew. Chem., Int. Ed. Engl. 2004, 43, 3882.
7 (a) P. W. Blosser, J. C. Gallucci and A. Wojcicki, J. Am. Chem. Soc.,
1993, 115, 2994; (b) P. W. Blosser, J. C. Gallucci and A. Wojcicki,
J. Organomet. Chem., 2000, 597, 125.
8 (a) J. N. Gerlach, R. M. Wing and P. C. Ellgen, Inorg. Chem., 1976, 15,
2959; (b) T. Matsuo, M. Tanaka and A. Sekiguchi, Chem. Commun.,
2001, 503 and references cited therein; (c) Y. Wang, H. Wang, H. Wang,
H.-S. Chan and Z. Xie, J. Organomet. Chem., 2003, 683, 39.
9 (a) A. D. Becke, J. Chem. Phys., 1993, 98, 5648; (b) A. D. Becke, Phys.
Rev. A., 1998, 38, 2398; (c) C. Lee, W. Yang and R. G. Parr, Phy. Rev.
B., 1988, 37, 785; (d) P. J. Hay and W. R. Wadt, J. Chem. Phys., 1985,
82, 299; (e) Gaussian 03, Revision B.03 , M. J. Frisch, et.al., Gaussian,
Inc., Pittsburgh, PA, 2003.
Notes and references
{ General procedure for the preparation of complex 2: complex 1 (2.040 g,
5.85 mmol) was dissolved in n-hexane (20 mL) under Ar. The resulting
yellow-brown solution was filtered, and ClCH2CMCCH2Cl (0.286 mL,
2.93 mmol) was added to the resulting solution under stirring. The solution
rapidly became brown and a dark-red precipitate of [Cp2TiCl2] was
formed. The mixture was allowed to stand in an argon atmosphere at 20 uC.
After 24 h the solution was filtered and evaporated to 10 ml under vacuum.
Upon cooling to 278 uC for 1 day, brown crystals were formed, which
were separated from the mother liquor by decanting, and washed with a
small amount of cold n-hexane and dried under vacuum. Yield of 2 was
0.454 g (65%), mp 211–212 uC (dec. at slow heating (3 uC per min); at fast
heating (20 uC per min) blows up at ca. 145–150 uC) under Ar.
{ Data for 2: elemental analysis calcd for C14H14Ti: C, 73.07; H, 6.13.
Found: C, 72.43; H 6.19%. 1H NMR (C6D6, 297 K): d 3.03 (s, 4H, CH2);
4.68 (s, 10H, Cp). 13C{1H} NMR (C6D6, 297 K): d 51.2 (CH2); 102.4 (Cp);
106.9 (CMC). IR (Nujol mull, cm21): 2029 (weak, nCMC). MS (70 eV, m/z):
230 [M]1, 178 [Cp2Ti]1, 113 [CpTi]1.
10 (a) E. D. Jemmis and K. T. Giju, Angew. Chem., Int. Ed. Engl., 1997, 36,
606; (b) E. D. Jemmis and K. T. Giju, J. Am. Chem. Soc., 1998, 120,
6952; (c) P. N. V. Pavan Kumar and E. D. Jemmis, J. Am. Chem. Soc.,
1988, 110, 125.
§ General procedure for the preparation of complex 3: Complex 1 (0.486 g,
1.38 mmol) was dissolved in toluene (7–8 mL) under Ar. The obtained
11 G. M. Sheldrick, Acta. Crystallogr., Sect. A, 1990, 46, 467.
12 SHELXL-93, G. M. Sheldrick, University of Go¨ttingen, Germany, 1993.
C h e m . C o m m u n . , 2 0 0 4 , 2 0 7 4 – 2 0 7 5
2 0 7 5