PREPARATION AND PROPERTIES OF RU-2(DTOLF)(4)CL - A SURPRISING ELECTRONIC-STRUCTURE CHANGE COMPARED TO RU-2(DTOLF)(4) (DTOLF=[(P-TOL)NCHN(P-TOL)](-))

Through the reaction between Ru-2(OAc)(4)Cl and molten HDto1F (di-p-tolylformamidine), Ru-2(Dto1F)(4)Cl (1) was isolated as a crystalline material in 75% yield, The green complex crystallizes as Ru-2(Dto1F)(4)Cl . C6H14 in the tetragonal space group P4/ncc, With a = 16.400 (3) Angstrom, c = 22.042(3) Angstrom, V = 5928 (2) Angstrom(3), and Z = 4. The Ru-Ru distance was found to be 2.370(2) Angstrom, which is ca, 0.1 Angstrom shorter than that in the known Ru-2(Dto1F)(4). On the basis of the temperature dependence of the effective magnetic moment, the compound is best described as a S = 3/2 system which undergoes zero-field splitting with D = 49.5 cm(-1). A sigma(2) pi(4) delta(2) pi*(2) delta* configuration is suggested for the ground state. Reversible oxidation occurs at 493 mV (Ag/AgCl) in the cyclic voltammogram, suggesting the accessibility of a Ru-2(Dto1F)(4)(2+) species.