Effect of cooperativity in lithium bonding on the strength of hydrogen bonding: (LiCN) n ···HX (n = 1–5, X = F, Cl) complexes as a working model

Cooperativity between the hydrogen bonding and σ-hole interaction in linear NCX···(NCH)n=2–5 and O3Z···(NCH)n=2–5 complexes (X = Cl, Br; Z = Ar, Kr): a comparative study

Quantum chemical calculations are performed to investigate the cooperativity of hydrogen bonding with halogen or aerogen bonding interactions in linear NCX···(NCH)n=2–5 and O3Z···(NCH)n=2–5 clusters, where X = Cl, Br and Z = Ar, Kr. To understand the cooperativity mechanism in these systems, the corresponding binary NCX···NCH and O3Z···NCH complexes are also considered. The binding distances, interaction energies, and bonding properties of the NCX···(NCH)n=2–5 and O3Z···(NCH)n=2–5 clusters are analyzed in detail. It is found that the cooperative effects in the hydrogen bonding tend to strengthen X···N and Z···N interactions. For both NCX···(NCH)n and O3Z···(NCH)n clusters, a small bond shrinkage is observed from n = 4 to n = 5, which suggests that the cooperativity effects are almost saturated in the larger clusters (n > 5). As the size of the X or Z atom is increased, the magnitude of the cooperative energy in these systems is also increased, which is mainly ascribed to changes in electrostatic potentials and orbital interactions. Our results indicate that the cooperative effects lead to a substantial change in the 14N nuclear quadrupole coupling constants of the NCH molecule.

Effect of cooperativity in lithium bonding on the strength of halogen bonding and tetrel bonding: (LiCN)n···ClYF3 and (LiCN)n···YF3Cl (Y = C, Si and n = 1-5) complexes as a working model

This paper reports results of cooperativity in lithium bonding on the strength of halogen bonding and tetrel bonding in complexes pairing CF3Cl and SiF3Cl with (LiCN)n complexes, where n varies from 1 to 5. Molecular geometries and stabilization energies of title complexes are calculated at the MP2 level with 6-311++G(d,p) basis set. Cooperative effects are found in terms of structural and energetic properties when lithium, halogen, and tetrel bonds are present in these complexes simultaneously. Our results reveal that strength of halogen and tetrel bondings are enhanced due to cooperativity of Li···N interactions in lithium bonded complexes. Good linear correlations between cooperativity parameters and electronic properties of complexes were established in the present study.