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https://doi.org/10.5562/cca4225

Halogen Bonding Induced Morphotropic Step in a Series of (Lead(II) Halogenide)–3-Halopyridine Complexes

Lucija Marić ; Department of Chemistry, University of Zagreb, Faculty of Science, Horvatovac 102a, 10000, Zagreb, Croatia
Nikola Bedeković ; Department of Chemistry, University of Zagreb, Faculty of Science, Horvatovac 102a, 10000, Zagreb, Croatia
Mladen Borovina ; Department of Chemistry, University of Zagreb, Faculty of Science, Horvatovac 102a, 10000, Zagreb, Croatia
Vladimir Stilinović ; Department of Chemistry, University of Zagreb, Faculty of Science, Horvatovac 102a, 10000, Zagreb, Croatia *

* Dopisni autor.

Prilozi: cca4225_supplement.pdf

Sažetak

A series of nine (lead(II) halogenide)–bis(3-halopyridine) complexes (halogen = Cl, Br I) have been prepared and studied by diffraction methods. For six of them their crystal and molecular structures were determined by single crystal diffraction. The compounds were found to crystallise as two structural types – the majority (8) constitute an isostructural monoclinic (P21/n) series of with unit cell parameters 4.14 Å < a < 4.47 Å; 15.19 Å < b < 16.15 Å; 11.37 Å < c < 11.76 Å; 92.1° < β < 94.1°, while one (PbCl2(3Ipy)2) was triclinic (P–1) with unit cell volume being approximately half of that of the monoclinic series. All the compounds were found to comprise [PbX2(3X'py)2]n chains with pairs of halogenide ions bridging between lead ions, which are overall coordinated by four coplanar halogenide ions and a pair of pyridine ligands in an octahedral coordination. The difference between the two structural types lies in different packing of the chains, affording different halogen bonding patterns. In all structures the halogen substituents on the pyridine ligands act as halogen bond donors and halogenide anions as acceptors. However, in the monoclinic series each chain interconnects with four neighbours, while in the triclinic with only two, also allowing for a closer approach of the donor and the acceptor atoms. Computational study of molecular electrostatic potential on chain fragments has shown that the triclinic structure is favoured in cases when the halogen bond donor with the most positive σ-hole (iodopyridine), and the best acceptors with the most negative MEP (chloride and bromide) are present.

Ključne riječi

isostructurality; halogen bonding; lead complex halogenide anion; halogenopyridine ligand

Hrčak ID:

347264

URI

https://hrcak.srce.hr/347264

Datum izdavanja:

17.1.2026.

Posjeta: 0 *