Diruthenium Alkynyl Compounds with Phosphonate Capping Groups

The reaction between Ru2(ap)4Cl (ap = 2-anilinopyridinate) and LiCC-4-Ph-P­(O)­(OtBu)2 afforded Ru2(ap)4-CC-4-Ph-P­(O)­(OtBu)2 (1), which was further reacted with LiCC-4-Ph-S­(CH2)2SiMe3 to yield trans-(4-Me3Si­(CH2)2S-Ph-CC)-Ru2(ap)4-CC-4-Ph-P­(O)­(OtBu)2 (2). trans-Ru2(DMBA)4(CC-4-Ph-P­(O)­(OtBu)2)2 (3; DMBA = N,N′-dimethylbenzamidinate) was obtained from the reaction between Ru2(DMBA)4(NO3)2 and either HCC-4-Ph-P­(O)­(OtBu)2 in the presence of Et3N or LiCC-4-Ph-P­(O)­(OtBu)2. Compounds 1–3 were characterized by HR-MS, X-ray diffraction, and voltammetric techniques, which revealed the retention of essential characteristics in molecular and electronic structures upon the phosphonate capping.