Selective synthesis and crystal structures of manganese(I) complexes with a bi- or tridentate terpyridine ligand

The crystal structures of two manganese(I) complexes with a different coordination mode of the supporting ligand are reported: fac-bromido­tricarbon­yl(4′-phenyl-2,2′:6′,2′′-terpyridine-κ2N,N′)manganese(I), [MnBr(C21H15N3)(CO)3], I, and cis-bromido­dicarbon­yl(4′-phenyl-2,2′:6′,2′′-terpyridine-κ3N,N′,N′′)manganese(I), [MnBr(C21H15N3)(CO)2], II. In both complexes, the manganese(I) atom is coordinated by terminal carbonyl ligands, a bromide ion, and a 4′-phenyl-2,2′:6′,2′′-terpyridine ligand within a distorted octa­hedral environment. In I, the metal ion is facially coordinated by three carbonyl ligands and the terpyridine ligand binds in a bidentate fashion. The non-coordinating nitro­gen atom in the terpyridine ligand is positioned on the side opposite to the bromido ligand. In II, the metal ion is coordinated by two carbonyl ligands in a cis configuration and the terpyridine ligand binds in a tridentate fashion; notably, one carbonyl and the trans bromido ligand are mutually disordered over two positions. In I, the complex mol­ecules are linked by C—H⋯Br hydrogen bonds. In II, aromatic π–π contacts are present, as well as pairs of C—H⋯Br and C—H⋯O hydrogen bonds.