An unusual norbornadiene coupling product: synthesis, characterization, and structure of the ruthenocene (C5Me5)Ru(eta-C5H4C9H11)

Treatment of (C5Me5)(2)Ru2Cl4 with excess norbornadiene (NBD) in refluxing ethanol yields the substituted ruthenocene complex (C5Me5)Ru(eta(5)-C5H4C9H 11), which possesses a cyclopentadienyl (Cp) ring bearing a tricyclo[4.2.1. 0(2,5)]-non-7-en-3-yl substituent. This compound has been characterized by NMR spectroscopy and X-ray crystallography. The substituted Cp ring is form ed by coupling of two NBD units, C-C bond cleavage, migration of one hydrog en atom from one carbon atom to another, and loss of a hydrogen atom (presu mably as HCl). Crystal data: monoclinic, space group P2(1)/n, with a = 10.0 285(5), b = 9.1801(5), c = 21.249(1) Angstrom, beta = 95.327(1)degrees V = 1947.9(2) Angstrom(3), Z = 4, wR(2) = 0.0580 for 4611 data and 291 paramete rs. (C) 1999 Elsevier Science S.A. All rights reserved.