Benjamin J. Coe, Samar Hayat, Roy L. Beddoes, Madeleine Helliwell, John C. Jeffery, Stuart R. Batten and Peter S. White
The series of mononuclear salts trans-[RuCl(pdma)2(L–L)]PF6 [pdma = o-phenylenebis(dimethylarsine); L–L = 4,4′-bipyridine (4,4′-bipy) 2, fumaronitrile (fmn) 4, di-4-pyridyl disulfide (dpds) 9 or trans-1,2-bis(4-pyridyl)ethylene (bpe) 11] have been synthesized by reaction of trans-[RuCl(pdma)2(NO)][PF6]2 with 1 equivalent of NaN3 in acetone at room temperature followed by reflux with an excess of L–L in butan-2-one. The salt trans-[RuCl(pdma)2(C5H5 NS)]PF66 (C5H5NS = pyridine-4-thione) was prepared similarly by using pyridine-4-thiol, and trans-[RuCl(pdma)2(C5H4 NSH)]PF68 (C5H4NSH = pyridine-4-thiol) was produced upon prolonged reflux of 9 in butan-2-one. Salts 6 and 8 are readily deprotonated by aqueous NaOH to give trans-[RuCl(pdma)2(C5H4NS)] 7 and 10. The dinuclear salts trans-[{RuCl(pdma)2}2(µ-L –L)][PF6]2 [L–L = pyrazine (pyz) 1, 4,4′-bipy 3, fmn 5 or bpe 12] have been synthesized by reaction of trans-[RuCl(pdma)2(NO)][PF6]2 with 1 equivalent of NaN3 followed by reflux with 1 equivalent of the monometallic salts trans-[RuCl(pdma)2(pyz)]PF6, 2, 4 or 11, respectively, in butan-2-one. The dimer trans-[{RuCl(pdma)2}2(µ-dpd s)][I3]213 was prepared by oxidation of 8 with iodine in Me2SO at room temperature. Single-crystal structures of 1, 3, 6 and 13 have been determined, and the extent of intermetallic electronic coupling in the dimers 1, 3, 5, 12 and 13 is assessed using cyclic voltammetry.