Syntheses and Crystal Structures of Ruthenium Complexes of 1,4,8,11-Tetraazacyclotetradecane, Tris(2-aminoethyl)amine (tren), and Bis(2-aminoethyl)(iminomethyl)amine. A Microporous Layered Structure Consisting of {[K(tren)](2)[RuCl(6)]}(n)()(n)()(-) and {(H(5)O(2))(4)[RuCl(6)]}(n)()(n)()(+).
The second method for the synthesis of cis-[Ru(III)Cl(2)(cyclam)]Cl (1) (cyclam = 1,4,8,11-tetraazacyclotetradecane), with use of cis-Ru(II)Cl(2)(DMSO)(4) (DMSO = dimethyl sulfoxide) as a starting complex, is reported together with the synthesis of [Ru(II)(cyclam)(bpy)](BF(4))(2).H(2)O (2) (bpy = 2,2'-bipyridine) from 1. The syntheses of Ru complexes of tris(2-aminoethyl)amine (tren) are also reported. A reaction between K(3)[Ru(III)(ox)(3)] (ox = oxalate) and tren affords fac-[Ru(III)Cl(3)(trenH)]Cl.(1)/(2)H(2)O (3) (trenH = bis(2-aminoethyl)(2-ammonioethyl)amine = monoprotonated tren) and (H(5)O(2))(2)[K(tren)][Ru(III)Cl(6)] (4) as major products and gives fac-[Ru(III)Cl(ox)(trenH)]Cl.(3)/(2)H(2)O (5) in very low reproducibility. A reaction between 3 and bpy affords [Ru(II)(baia)(bpy)](BF(4))(2) (6) (baia = bis(2-aminoethyl)(iminomethyl)amine), in which tren undergoes a selective dehydrogenation into baia. The crystal structures of 2-6 have been determined by X-ray diffraction, and their structural features are discussed in detail. Crystallographic data are as follows: 2, RuF(8)ON(6)C(20)B(2)H(34), monoclinic, space group P2(1)/c with a = 12.448(3) Å, b = 13.200(7) Å, c = 17.973(4) Å, beta = 104.28(2) degrees, V = 2862(2) Å(3), and Z = 4; 3, RuCl(4)O(0.5)N(4)C(6)H(20), monoclinic, space group P2(1)/a with a = 13.731(2) Å, b = 14.319(4) Å, c = 13.949(2) Å, beta = 90.77(1) degrees, V = 2742(1) Å(3), and Z = 8; 4, RuKCl(6)O(4)N(4)C(6)H(28), trigonal, space group R&thremacr; with a = 10.254(4), c = 35.03(1) Å, V = 3190(2) Å(3), and Z = 6; 5, RuCl(2)O(5.5)N(4)C(8)H(22), triclinic, space group P&onemacr; with a = 10.336(2) Å, b = 14.835(2) Å, c = 10.234(1) Å, alpha = 90.28(1) degrees, beta = 90.99(1) degrees, gamma = 92.07(1) degrees, V = 1567.9(4) Å(3), and Z = 4; 6, RuF(8)N(6)C(16)B(2)H(24), monoclinic, space group P2(1)/c, a = 10.779(2) Å, b = 14.416(3) Å, c = 14.190(2) Å, beta = 93.75(2) degrees, V = 2200.3(7) Å(3), and Z = 4. Compound 4 possesses a very unique layered structure made up of both anionic and cationic slabs, {[K(tren)](2)[Ru(III)Cl(6)]}(n)()(n)()(-) and {(H(5)O(2))(4)[Ru(III)Cl(6)]}(n)()(n)()(+) (n = infinity), in which both sheets {[K(tren)](2)}(n)()(2)(n)()(+) and {(H(5)O(2))(4)}(n)()(4)(n)()(+) offer cylindrical pores that are occupied with the [Ru(III)Cl(6)](3)(-) anions. The presence of a C=N double bond of baia in 6 is judged from the C-N distance of 1.28(2) Å. It is suggested that the structural restraint enhanced by the attachment of alkylene chelates at the nitrogen donors of amines results in either the mislocation or misdirection of the donors, leading to the elongation of the Ru-N(amine) distances and to the weakening of their trans influence. Such structural strain is also discussed as related to the spectroscopic and electrochemical properties of the cis-[Ru(II)L(4)(bpy)](2+) complexes (L(4) = (NH(3))(4), (ethylenediamine)(2), and cyclam).
Sakai
Ken
K
Department of Industrial Chemistry, Seikei University, Kichijoji-Kitamachi, Musashino, Tokyo 180, Japan.
Yamada
Yasutaka
Y
Tsubomura
Taro
T