Investigation of interactions in Lewis pairs between phosphines and boranes by analyzing crystal structures from the Cambridge Structural Database

Abstract

The interactions between phosphines and boranes in crystal structures have been investigated by analyzing data from the Cambridge Structural Database (CSD). The interactions between phosphines and boranes were classified into three types; two types depend on groups on the boron atom, whereas the third one involves frustrated Lewis pairs (FLPs). The data enabled geometric parameters in structures to be compared with phosphine-borane FLPs with classical Lewis pairs. Most of the crystal structures (78.1%) contain BH as the borane group. In these systems, the boron-phosphorus distance is shorter than systems where the boron atom is surrounded by groups other than hydrogen atoms. The analysis of the CSD data has shown that FLPs have a tendency for the longest boron-phosphorus distance among all phosphine-borane pairs, as well as different other geometrical parameters. The results show that most of the frustrated phosphine-borane pairs found in crystal structures are bridged ones. The minority of non-bridged FLP structures contain, beside phosphorus and boron atoms, other heteroatoms (O, N, S for instance).

Dihydrogen Bond in the Aminoborane Complex of a Nicergoline Intermediate

“…Deviations of the B–H bond length of about 0.05 Å were reported, however, for terminal atoms, was about 0.1 Å [20]. Investigations based on CSD data mining, e.g., [21], are inevitably based on partially biased data, and the authors highlight the inaccuracy in hydrogen atom positions. By contrast, Crabtree et al, in 1996, used normalized B–H and N–H bond distances to avoid systematic underestimation of the bond lengths in the CSD structures [9].…”

Binding of metal ions and water molecules to nucleic acid bases: the influence of water molecule coordination to a metal ion on water–nucleic acid base hydrogen bonds

“…By conducting a structural databases survey, significant insights into molecular structure and interactions can be achieved (Milovanović et al, 2018;Janjić et al, 2013;Sredojević et al, 2012;Groom et al, 2016;Majerz & Dziembowska, 2018;Grothe et al, 2017).…”