title: Complexation of different transition metals with 4,4'-dimethyl-2,2'-bipyridine: Crystal structure, UV spectra and Hirshfeld surfaces.
abstract: Four new complexes, [Co(dmbpy)2(dca)2]·CH3OH (1), [Ni(dmbpy)2(dca)2]·CH3OH (2), [Zn(dmbpy)2(dca)2]·(3) and [Cu(dmbpy)2(OH)2]·5H2O (4) (dca=dicyanamide), derived from 4,4'-dimethyl-2,2'-bipyridine (dmbpy) have been synthesized and characterized by elemental analysis, TGA and single-crystal X-ray diffraction. Crystal structures and Hirshfeld surfaces analysis revealed that the complexes 1-3 were mainly supported by OH⋯N, CH⋯N and π⋯π intermolecular interactions, and for complex 4, the uncoordinated water molecules play a key role in the construction of the 3D stacking motif. UV spectrum measurements demonstrate that all of the complexes show typical metal to ligand charge transfer (MLCT) absorption bands between 301 and 306nm. Moreover, after complexation, the absorption maximum bands about intraligand π→π* transitions similarly show slightly red shift compared to dmbpy ligand, consisting with the DFT calculations.
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, PR China.
authors.forename: Li-Jing
authors.initials: LJ
authors.lastname: Yang
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, PR China.
authors.forename: Qing-Ling
authors.initials: QL
authors.lastname: Liu
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, PR China.
authors.forename: Ming-Xin
authors.initials: MX
authors.lastname: Wang
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, PR China.
authors.forename: Lian-Shuai
authors.initials: LS
authors.lastname: Gu
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, PR China.
authors.forename: Yang-Hui
authors.initials: YH
authors.lastname: Luo
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, PR China. Electronic address: chmsunbw@seu.edu.cn.
authors.forename: Bai-Wang
authors.initials: BW
authors.lastname: Sun
keywords: Crystal structure; DFT calculations; Hirshfeld surface; UV spectra