The Investigation by infrared spectroscopy of the structural properties and the host-guest interactions of cyclohexyl mercaptan tetracyanonickel [M(CHT)2Ni(CN)4]. G clathrates

In this study Hofmann - type clathrates, formulated as M(Cyclohexyl mercaptan)2Ni(CN)4.G (M = Ni, Cd, Co, Mn or Zn; G = Benzene, 1,3-Dichlorobenzene 1,4-Dioxane), areobtained chemically for the first time. Infrared spectra of the clathrates are recorded with FTIRspectrometer in the spectroscopic region of the 4000 cm-1 - 400 cm-1. The assignments areperformed for the ligand molecule, the Ni(CN)4 groups and the guest molecules separately. Thevibrational frequencies of the clathrates are compared with frequencies of free Cyclohexylmercaptan molecule. It was observed that some of these vibrational frequencies are shifted inrespect to the free molecule?s vibrational frequencies due to clathrates formation. The observedfrequency shifts arise because of bounding metal and coupling of metal ligand vibrationalmodes.The Ni(CN)4-2 anions and M(Cyclohexyl mercaptan)2+2 cations in the host structures ofthe clathrates forms a three dimentional polymeric structure. In this structure the Ni atoms aresurrounded in the squared form by four C atoms of cyanide anions. M atoms are surroundedalso octahedrally by four N atoms of cyanide anions and two S atoms of ligand molecule. Theligand molecule is bound to M atom directly through S atom. The Ni(CN)4+2 are bounded toeach other by M(Cyclohexyl mercaptan)2+2 in the three dimensional lattice form. There arecavities, namely α, in the host structure formed. Guest molecules accommodates also in thesecavities.Key Words: Benzene, Cyclohexyl mercaptan, 1,3-Dichlorobenzene, 1,4-Dioxane,Hofmann type Clathrates, Infrared Spectroscopy.