Experimental and Theoretical Study of Tetrel Bonding and Noncovalent Interactions in Hemidirected Lead(II) Phosphorodithioates: An Implication on Crystal Engineering

Abstract

The importance of tetrel bonds (TtBs) in spontaneous self-assembly has been highlighted in two new lead(II) complexes: i.e. Pb[S2P{OC6H4(4-C(CH3)3)}2]2 (1) and Pb[S2P{OC6H4(4-C2H5)}2]2 (2), which were successfully isolated and characterized by FT-IR, UV–vis and multinuclear NMR (31P, 1H and 13C) spectroscopy. The structures of both complexes have been confirmed by single-crystal X-ray diffraction analyses. Interestingly, lead is coordinated by three sulfur atoms in 1 but by four sulfur atoms in 2, due to stereochemically active lone pair electrons, thus leading to trigonal-pyramidal and tetragonal-pyramidal geometries, respectively. Complex 1 is the first example of a lead(II) dithiophosphate wherein the lead(II) center is coordinated to three S atoms. These complexes are stabilized at a lower coordination number and display hemidirected structures that allow forming σ-hole bonds. The lead(II) center establishes short contacts with sulfur atoms to form Pb···S TtBs that contribute to the construction of a self-assembled dimer in 1 but to a supramolecular polymer in 2. The supramolecular assemblies are further stabilized by Pb···π TtB interactions. The attractive nature of TtBs has been studied by DFT calculations and characterized using a combination of Bader’s quantum theory of atoms-in-molecules (QTAIM) and noncovalent interaction plot (NCI plot) index based on a reduced density gradient (NCI-RDG) analysis. A systematic Hirshfeld surface analysis facilitates a comparison of intermolecular interactions such as C–H···π, π···π, Pb···S, and Pb···π in both complexes, which play a crucial role in the crystal engineering.

On the pivotal role of tetrel bonding in the supramolecular architectures of PbII–NCS complexes with chelating thiosemicarbazide derivatives

“…44 In this context, lead, with its large atomic radius and significant polarizability, forms strong and directionally specific interactions with a variety of electron donors, including π-systems. 45 These tetrel bonding interactions are instrumental in dictating the assembly and properties of crystal networks. 24–45 This approach in crystal engineering not only broadens the horizon for creating new materials but also offers deep insights into the fundamental interactions governing the assembly of complex crystal structures.…”

“…45 These tetrel bonding interactions are instrumental in dictating the assembly and properties of crystal networks. 24–45 This approach in crystal engineering not only broadens the horizon for creating new materials but also offers deep insights into the fundamental interactions governing the assembly of complex crystal structures.…”

Conformation-Associated C···dz2-PtII Tetrel Bonding: The Case of Cyclometallated Platinum(II) Complex with 4-Cyanopyridyl Urea Ligand

“…Particularly, metal-involved halogen bonds [31][32][33][34][35][36], chalcogen bonds [37], spodium bonds [20], pnictogen bonds [38], and πh/C•••M interactions [39][40][41][42][43] have been recognized. To contrast, in most examples of metal-involved TtB, a metal (commonly, tin or lead) is a σor π-hole donor, i.e., electrophilic site [44][45][46][47]. These interactions are the focus of many studies [48,49] due to importance of lead and tin coordination compounds for materials science [50][51][52][53].…”

Thallium(i)phosphorodithioates containing intra- and intermolecular π-hole triel bonds

“…The present investigation is an extension of our ongoing research interest in non-covalent interactions. 40–46 We herein designed and characterized two new diaryldithiophosphato- S , S ′-thallium compounds, corresponding to Tl + [S 2 P{OC 6 H 3 (2,5-(CH 3 ) 2 )} 2 ] − ( 1 ) and Tl + [S 2 P{OC 6 H 3 (3,5-(CH 3 ) 2 )} 2 ] − ( 2 ), consisting of a π-hole at the Tl atom, which results in Tl–C/S triel bonds. In this study, we placed particular focus on the self-assembled structures formed by Tl( i )⋯S, Tl( i )⋯C TrBs, anagostic, and other non-covalent interactions.…”

“…17, The present investigation is an extension of our ongoing research interest in non-covalent interactions. [40][41][42][43][44][45][46] We herein designed and characterized two new diaryldithiophosphato-S, S′-thallium compounds, corresponding to Tl + [S 2 P{OC 6 H 3 (2,5-…”