Mono- and dinuclear high-spin half-sandwich manganese(II) complexes containing acetylide and TMEDA ligands

The d(5) high-spin Mn-II half-sandwich complexes [Mn(Cequivalent toCR)(MeC5H4)(tmeda)] (R = SiMe3 2; Ph 3; tBu 4; Cequivalent toCSiMe(3) 5; Cequivalent toCPh 6; tmeda = N,N,N',N'-tetramethylethylenediamine) were prepared by the reaction of [Mn(MeC5H4)(2)(tmeda)] (1) with 1 equiv. of the corresponding acetylene or the trimethyltin acetylide. The dinuclear complexes [Mn(Cequivalent toC-Cequivalent toCSiMe(3))(2)(tmeda)](2) (7) and [Mn-2(MeCP)(2)(mu(1)-tBuCequivalent toC)(2)(mu(1)-tmeda)] (8), which contain Mn-Mn bonds, were synthesized by treating 1 with an excess of HCequivalent toC-Cequivalent toCSiMe(3) or HCequivalent toCtBu, respectively. Dinuclear complexes of the type [(MeC5H4)(tmeda)MnCequivalent toC-X=Cequivalent toCMn(tmeda) (C5H4Me)] [X = 1,3-C6H4 9; 1,4-C6H4 10; 4,4'-(C6H4)(2) 11] were obtained by treatment of 1 with 0.5 equiv. of the corresponding acetylides 1,3-C6H4(Cequivalent toCSnMe(3))(2), 1,4-C6H4(Cequivalent toCSnMe(3))(2) and 4,4'-(C6H4)(2)(Cequivalent toCSnMe(3))(2) in benzene for 24 h to yield the corresponding dinuclear complexes in very good yields. All the mono- and dinuclear compounds have been characterized by NMR, IR, Raman spectroscopy and elemental analyses. X-ray diffraction studies have been performed on complexes 3 and 5-11. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)