Preparation and characterization of pentamethylcyclopentadienylrhodium(III) and iridium(III), and (arene)ruthenium(II) complexes of 1,8-bis(diphenylphosphinomethyl)naphthalene

1,8-Bis(diphenylphosphinomethyl)naphthalene (1,8-dpmn) reacted with [(arene)RuCl2]2 (1) or [Cp*MCl2]2 (2: M=Rh; 3: M=Ir) to generate the corresponding diphosphine-bridged complexes, [{(arene)RuCl2}2(1,8-dpmp-P,P′)] (4) (arene=p-cymene (a), 1,2,3-Me3C6H3 (b), 1,2,3,4-Me4C6H2 (d), 1,2,3,5-Me4C6H2 (d), C6Me6 (e)) or [(Cp*MCl2)2(1,8-dpmp-P,P′)] (5: M=Rh; 6: M=Ir). Homonuclear complexes [{(p-cymene)RuCl2}(1,8-dpmp-P,P′){(arene)RuCl2}] 7ab and 7ad bearing different arene groups were prepared by the reactions of 1a with 1b (or 1d). They existed as two isomers in solution. Reactions of 2 with 1 or 3 gave heteronuclear complexes [(Cp*RhCl2)(1,8-dpmp-P,P′) {(arene)RuCl2}] (8) and [(Cp*RhCl2)(1,8-dpmp-P,P′)(Cp*IrCl2)] (10). The heteronuclear complexes of iridium–ruthenium 9 were generated from 1 to 2. Complexes 1, 2 and 3 reacted with 1,8-dpmp in the presence of AgOTf to give the cationic complexes, [(arene)RuCl(1,8-dpmp-P,P′)](OTf) (11) or [Cp*MCl(1,8-dpmp-P,P′)](OTf) (12: M=Rh; 13: M=Ir) that showed the presence of isomers in solution. They were treated with Ag(OTf) to afford the Cl-bridged complexes, [{(p-cymene)Ru(μ-Cl)}2(1,8-dpmp-P,P′)](OTf)2 (15a) or [{Cp*M(μ-Cl)}2(1,8-dpmp-P,P′)](OTf)2 (16: M=Rh; 17: M=Ir). Complexes 16 and 17 cleaved the Cl-bridges with xylyl or mesityl isocyanide to generate the dimeric isocyanide complexes [{Cp*MCl(RNC)}2(1,8-dpmp-P,P′)](OTf)2 (18: M=Rh; 19: M=Ir). X-ray analyses of 5, 8b, 10, 11a, 12, 15a and 18b were performed.