Metal-directed self-assembly of transition metal heterometallascorpionates

The heterobimetallic complexes [Co(L tzE ) 3 K(THF) 2 ] [L tzE = [{4,5-(P(E)Ph 2 ) 2 }tz] − ; tz = 1,2,3-triazole; E = S( 3 ), Se( 4 )] featuring high-spin cobalt centres, and [Ni(L tzE ) 3 K(THF) 2 ] [E = S( 5 ), Se( 6 )] were synthesized through the self-assembly reaction of HL tzE [E = S( 1 ), Se( 2 )], KOH or K 0 and MCl 2 (M = Co, Ni). Compounds 3-6 exhibit an unusual metallascorpionate-type anion formed by the coordination of three triazole units via a κ 2 - N , E mode to the transition-metal atom, and this anion further coordinates to a potassium cation through a κ 3 - N ′, N ′′, N ′′′ fashion. Compounds 3 and 5 were used in the synthesis of 3d-metal heterometallascorpionates [M(L tzS ) 3 Cu(PPh 3 )] [M = Co, ( 7 ), M = Ni ( 8 )] and the bimetallic complex [Ni(L tzE ) 3 Ni(NO 3 )(THF)] ( 9 ) through metathesis reactions, pointing to stable metallascorpionate anions in solution. The solution behavior of 3-9 was investigated by UV-visible spectroscopy, high-resolution mass spectrometry, electrochemical methods and by magnetic-susceptibility measurements. The molecular structures of 3-6 , 8 and 9 were determined by single-crystal X-ray diffraction studies and exhibit M M′ distances ranging from 3.52 to 3.88 Å. 3d metal-based heterometallascorpionates featuring high-spin Co( ii ) and Ni( ii ) centers were prepared and their structural, magnetic and electronic properties investigated.