COMPOUNDS CONTAINING LINKED MULTIPLY-BONDED DIMETAL UNITS .2. AN ANTIFERROMAGNETIC COMPOUND CONTAINING INFINITE CHAINS OF RU2(O2CR)4+ UNITS LINKED BY BRIDGING PHENAZINE MOLECULES

The polymeric [Ru2(O2CC2H5)4(phz)]BF4 was prepared by reaction of (RU2(O2CC2H5)4(H2O)2]BF4 with phz (phenazine). Crystals of [Ru2(O2CC2H5)4(phz)]BF4 were obtained by a diffusion technique in which a dichloromethane solution of [Ru2(O2CC2H5)4(H2O)2]BF4 was carefully layered by a benzene solution containing an excess amount of phz. The compound has been characterized by X-ray crystallography and magnetic susceptibility measurements from ca. 2 to ca. 300 K. The space group is P1BAR, and there are two formula units per unit cell with a = 11.669 (5) angstrom, b = 14.471 (2) angstrom, c = 8.963 (1) angstrom, alpha = 103.96 (1)-degrees, beta = 96.743 (2)-degrees, and gamma = 70.237 (2)-degrees. The phz ligands connect the dinuclear species into kinked chains that all run parallel to the 111 direction. There are two crystallographically independent RU2(O2CC2H5)4+ cations with Ru(1)-Ru(1)' = 2.2756 (6) angstrom, Ru(2)-Ru(2)' = 2.2747 (7) angstrom, Ru(1)-N(1) = 2.436 (4) angstrom, and Ru(2)-N(2) = 2.443 (5) angstrom. The BF4- ions occupy general positions between the chains. The compound is antiferromagnetic with a magnetic moment of ca. 4.3 mu(B) at 300 K that tends toward zero as 0 K is approached (1.72-mu(B) at 2.7 K).