Dinuclear Ir(III) Complex with an Unusual eta(1):eta(3)-allylic Bridging Ligand from the Double C-H Activation of 2,5-Dimethylthiophene

作者：Grochowski Matthew R; Brennessel William W; Jones William D^*

来源：Journal of Chemical Crystallography, 2011, 41(6): 829-833.

DOI：10.1007/s10870-011-0006-x

• C-H activation
• eta(1):eta(3)-allyl
• Thiophene

The unique dinuclear Ir(III) complex (Cp*IrCl) (mu-H)[mu-(eta(1):eta(3)-C6H6S)](IrCp*) (1) has been synthesized and characterized by NMR spectroscopy (H-1 and C-13), elemental analysis, and single crystal X-ray diffraction. It is the first structurally determined complex in which an activated thiophene ligand displays an eta(3)-allylic interaction. 1 appears to form from successive C-H bond activations of 2,5-dimethylthiophene, resulting in its bridging the two iridium centers. The eta(3)-allylic interaction occurs with one of the Ir centers and has Ir-C-thio bond lengths ranging from 2.133(5)-2.207(5) angstrom; the C-C double bond involved in the interaction has a bond length of 1.438(7) angstrom compared to 1.348(8) angstrom for the uncoordinated C-C double bond. The 3-carbon of the thiophene ring bridges both iridium centers with bond lengths of 2.036(5) angstrom and 2.208(5) angstrom. 1 crystallizes in space group P-1 with cell constants a = 8.6303(6) angstrom, b = 9.0153(6) angstrom, c = 18.1089(12) angstrom, alpha = 84.728(1)degrees, beta = 87.534(1)degrees, gamma = 64.373(1)degrees, and Z = 2. The structure was solved by direct methods and refined to R = 0.0363 (F-2 > 2 sigma(F-2)) and wR = 0.0851 (F-2). The NMR data indicate the solution state structure is consistent with the solid state structure.

• 出版日期2011-6