PREPARATION AND STOICHIOMETRIC AND CATALYTIC REACTIVITY OF HYDRIDO ORGANOMETALLIC RUTHENIUM COMPLEXES - X-RAY CRYSTAL-STRUCTURE OF [RUH(ETA-5-C8H11)2]BF4

Protonation of Ru(eta-4-C8H12)(eta-6-C8H10) by HBF4.Et2O at -80-degrees-C initially produces [RuH(eta-4-C8H12)(eta-6-C8H10)]BF4(1). Complex 1 isomerizes in solution to [RuH(eta-5-C8H11)2]BF4 (2) through a mechanism that has been specifically studied by freezing the reaction through deprotonations. The X-ray crystal structure of 2 shows the complex to be a ruthenium(IV) hydride lacking any agostic interactions: space group C2h6-C2/c; a = 10.962 (1) angstrom, b = 9.922 (1) angstrom, c = 15.077 (1) angstrom, beta = 98.71 (1)-degrees; V = 1620.9 (5) angstrom3; Z = 4. Complex 2 reacts with acetone to give an equilibrium mixture of 2 and [Ru(eta-5-C8H11)(eta-4-C8H12)-(acetone)]BF4 (3), thus demonstrating the ease of hydrogen transfer in the system. The reaction of 1 with S (S = MeCN, H2O) produces [Ru(eta-5-C8H11)S3]BF4 (5 and 4, respectively), while with C5Me5H the complex [Ru(eta-5-C5Me5)(C8H12)]BF4 (7) is formed and shown by H-1 and C-13 NMR studies to adopt a ruthenium (II) structure with an agostic interaction. With cyclopentene, a similar complex is obtained for which the formula [Ru(eta-5-C5H5)(C8H12)]BF4 (9) is proposed. 1 also reacts with PMePh2 to yield [Ru(eta-5-C8H11)(PMePh2)3]BF4 (6) and with C6Me6 to yield [Ru(eta-5-C8H11)(eta-6-C6Me6)]BF4 (10). Complex 1 or its derivatives are catalysts for 1-alkene isomerization, ethylene dimerization, and ring-opening polymerization of norbornene.