Synthesis and Characterization of the Series of Compounds Ru(2)(O(2)CMe)(x)()(admp)(4)(-)(x)()Cl (Hadmp = 2-Amino-4,6-dimethylpyridine, x = 3, 2, 1, 0).
The reaction between Ru(2)(O(2)CMe)(4)Cl and Hadmp (Hadmp = 2-amino-4,6-dimethylpyridine) under different conditions has been investigated. By conducting the reaction in a methanol solution at room temperature the product obtained was Ru(2)(admp)(O(2)CMe)(3)Cl (1). In a melt reaction at 65 degrees C the product isolated is Ru(2)(admp)(2)(O(2)CMe)(2)Cl (2); at 100 degrees C it is Ru(2)(admp)(3)(O(2)CMe)Cl (3); and at 140 degrees C it is Ru(2)(admp)(4)Cl (4). The generality of these reactions was confirmed by the deliberate preparation of Ru(2)(chp)(3)(O(2)CMe)Cl (5) and [Ru(2)(DPhTA)(3)(O(2)CMe)(NCMe)(2)][BF(4)] (6). The structures of 1, 2, and 3 were determined by X-ray crystallography. The structure of 1 was determined from crystals of 1.3CH(2)Cl(2) (C(16)H(24)Cl(7)N(2)O(6)Ru(2)), triclinic, P&onemacr; (No. 2), with a = 11.578(3) Å, b = 12.5607(13) Å, c = 20.903(3) Å, alpha = 99.927(14) degrees, beta = 100.222(9) degrees, gamma = 102.07(2) degrees, Z = 4; that of 2, from crystals of 2.2.5CH(2)Cl(2) (C(21)H(30)Cl(7)N(4)O(4)Ru(2)), monoclinic, P2(1)/n (No. 14), with a = 13.091(3) Å, b = 19.098(4) Å, c = 13.720(3) Å, beta = 105.51(3) degrees; that of 3, from crystals of 3.Hadmp.C(6)H(6) (C(36)H(46)ClN(8)O(2)Ru(2)), monoclinic, P2(1)/n (No. 14), with a = 15.979(2) Å, b = 14.9294(14) Å, c = 17.131(4) Å, beta = 109.21(2) degrees. The magnetic susceptibilities and electrochemistry of the four title compounds were also studied. It was observed that while compounds 1, 2, and 3 display magnetic moments compatible with the presence of three unpaired electrons and all yield stable one-electron oxidation products, 4 shows only one unpaired electron and the product of its one-electron oxidation decays sufficiently rapidly that no return wave is observed.
Cotton
F. A.
FA
Department of Chemistry, P.O. Box 300012, Texas A&M University, College Station, Texas 77842-3012.
Yokochi
A.
A