Theoretical study of the structure and water affinity of [M(18C6)(HFA)2] complexes for M = Zn, Cu, Hg, Co, Ni, and Pt

• Published in: Russian journal of inorganic chemistry 2016-07, Vol.61 (7), p.846-857
• Main Authors: Kochnev, V. K., Sevast’yanov, V. G., Kuznetsov, N. T.
• Format: Article
• Language: English
• Subjects: Cations; Chemistry; Chemistry and Materials Science; Cobalt; Gas phases; Inorganic Chemistry; Mathematical analysis; Mercury (metal); Nickel; Platinum; Stability analysis; Theoretical Inorganic Chemistry
• ISSN: 0036-0236; 1531-8613
• DOI: 10.1134/S0036023616070111

The structures of the [M(18C6)] 2+ cations, where M = Zn, Cu, Hg, Ni, Co, and Pt, and cis - and trans -[M(18C6)(HFA) 2 ]/[M(18C6)(NO 3 ) 2 ] molecules in the gas phase have been calculated by the density functional theory method in the B3LYP/6-31G*//6-311++G** + LanL2Dz approximation. Geometry optimization has been performed, and the strength of binding of the central cation to the crown ether (18C6) and the degree of structural similarity of the [M(18C6)(HFA) 2 ] compounds for different central atoms M have been evaluated. For all [M(18C6)(NO 3 ) 2 ]/[M(18C6)(HFA) 2 ] molecules (M = Zn, Cu, Hg, Ni, Co, Pt), the vertical ionization potential and the vertical electron affinity have been calculated. These parameters are of interest for analysis of the stability of volatile compounds [M(18C6)(HFA) 2 ] to donor–acceptor interactions with other components of the gas phase, for example, with water vapor, which is usually a Lewis base with respect to the systems in question and can donate electron density in the course of complexation with the central atom. The propensity of the [M(18C6)(NO 3 ) 2 ]/[M(18C6)(HFA) 2 ] molecules to react with water is considered for a wider range of metals M 2+ = Ba 2+ , Sr 2+ , Pb 2+ , Mn 2+ , Cd 2+ , Zn 2+ , Cu 2+ , Hg 2+ , Co 2+ , Ni 2+ , and Pt 2+ , with taking into account the degree of matching between the ionic radii of M 2+ cations and the 18C6 cavity size.