Study Substituted Benzyl Pyrazine Cations Effect On The Stacking Of [Ni（mnt）₂]^n-（n=1,2） Anions And Complexes Properties

Ion-pair charge transfer compounds of [Ni（mnt）₂]^n-with a variety of counter-ions(mnt^n-=maleonitriledithiolate; n=1,2) have been widely studied due to their novelproperties in the areas of conducting and magnetic materials, dyes, no^n-linear optics,catalysis and so on. These special properties arise principally from the special planarmolecular geometry and delocalizing electron structure of [Ni（mnt）₂]^n-anion. It is animportant functional compounds in the frontier of inorganic chemistry field. There are richweak interactions in dithiolate metal compounds. For theoretical and practical meanings, itis important to synthesize new dithiolate metal compounds with new structure and functionthat could study the relationship between the weak interaction and the structure, andinvestigate the relationship between the structure and the property of resulted compounds.The main contents are as follows: eight new compounds of [[RBzPz]n[Ni（mnt）₂(]n=1,2; R=F, Cl, Br, I, CNï¼›R=p-Substituted; Bz=benzyl; Pz=pyrazine; mnt^n-=maleonitriledithiolate)were synthesized and characterized by elemental analysis （EA）, IRspectra, UV-Vis spectra, CV. Crystal structures of the eight compounds were determined,which show that compound [FBzPz]₂[Ni（mnt）₂]（1a and1b） and compound[BrBzPz]₂[Ni（mnt）₂]（2a and2b） appear isomerism due to the influence of solvent.Compound [FBzPz]₂[Ni（mnt）₂]（1b） and compound [BrBzPz]₂[Ni（mnt）₂]（₂b） bothcrystallize in monoclinic, space group P₂（1）/c. The compounds [FBzPz]₂[Ni（mnt）₂]（1a）,[BrBzPz]₂[Ni（mnt）₂]（₂a）,[CNBzPz]₂[Ni（mnt）₂]（3）,[ClBzPz]₂[Ni（mnt）₂]（4） and[IBzPz]₂[Ni（mnt）₂]（5） are isostructural and crystallize in the monoclinic, space group P₂（1）/n. Anions and cations are respectively stacking into column, there are four anionscolumn around each cations column, so are the cations column，but the weak interactionsin cations column are different: the compounds1a,₂a,4exist the π…π interaction andlp…π interaction commonly, while the compound3exists a rare charge assisted π…πinteraction between CN group, forming a delocalized big Ï€ bond that all atoms of the big Ï€ bond are in the same plane base. This is the first case in the complexes. Compound5is inpresence of C-H…N hydrogen bond, not the expected lp…π interaction. Compounds[FBzPz][Ni（mnt）₂]（6）,[BrBzPz]₂[Ni（mnt）₂]（7） and [IBzPz][Ni（mnt）₂]（8） are isostructuraland crystallize in triclinic system with space group P-1, crystals show a layered alternatelystacking which consisted of cationic layer and ions symbiosis layer. In the cations layer, afour-propeller-shaped unit has been fomed by lp…π interaction between terminal N atomin pyrazine ring and the adjacent pyrazine ring，which is the first case in the complexes.