Halogen Contacts‐Induced Unusual Coloring in Bi^III Bromide Complex: Anion‐to‐Cation Charge Transfer via Br⋅⋅⋅Br Interactions

Abstract

A yellow bromobismuthate {(2-BrPy) H}[BiBr ] (1, 2-BrPy=2-bromopyridinium) transforms into the unusually deeply colored cherry-red (2-BrPyH) [BiBr ] (2). A combination of structural studies and theoretical calculations confirms that the appearance of short non-covalent Br⋅⋅⋅Br interactions (≈3.3 Å) in 2 is responsible for the anion-to-cation charge transfer (LP(Br )→σ*(Br-C)), yielding dramatic changes in optical behavior. This effect opens the way towards novel halogen bonding-templated halometalate-based hybrid materials with enhanced optical properties.

Symmetrical Noncovalent Interactions Br···Br Observed in Crystal Structure of Exotic Primary Peroxide

“…The quantum theory of atoms in molecules (QTAIM) analysis [27] and independent gradient model analysis of noncovalent interactions based The appropriate bond critical point for intermolecular noncovalent interactions Br···Br in the single-crystal XRD structure of 3 was found during the QTAIM analysis. The properties of electron density in this bond critical point are typical for noncovalent interactions [29,30] and, in particular, for similar weak contacts halogen···halogen [31][32][33]. Energy for these contacts (2.2-2.5 kcal/mol) was estimated using the procedures developed by Tsirelson et al for non-covalent contacts involving bromine atoms using the equations E int = 0.58(−V(r)) or E int = 0.57G(r), respectively [28].…”

2,2′‐Azobispyridine in Phosphorus Coordination Chemistry: A New Approach to 1,2,4,3‐Triazaphosphole Derivatives

“…This approach has already been successfully used by us upon studies of different noncovalent interactions (viz. hydrogen, halogen and chalcogen bonding, metallophilic interactions, stacking) in various organic, organometallic, and coordination compounds . The QTAIM analysis did not reveal the presence of appropriate bond critical points (3, –1) for the intramolecular noncovalent interactions N ··· P in 2 , 4 , and 6 , and negligible values of the Wiberg bond indices for these contacts (viz.…”

The X-ray constrained wavefunction of the [Mn(CO)4{(C6H5)2P-S-C(Br2)-P(C6H5)2}]Br complex: a theoretical and experimental study of dihalogen bonds and other noncovalent interactions

“…*(C13-H13) interactions. By means of a comparison, for the weak BrÁ Á ÁBr interactions in {(2-BrPy) 2 H}[BiBr 4 ] and 2-(BrPyH) 2 [BiBr 5 ], which are dominated by electrostatics, the stabilizing energy is only 0.9 and 5.6 kcal mol À1 , respectively (Adonin et al, 2017).…”