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Bi 2 Pt( hP 9) by Low‐Temperature Reduction of Bi 13 Pt 3 I 7 : Reinvestigation of the Crystal Structure and Chemical Bonding Analysis
Author(s) -
Kaiser Martin,
Baranov Alexey I.,
Ruck Michael
Publication year - 2014
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.201400331
Subject(s) - crystallography , bismuth , platinum , stacking , crystal structure , chemistry , octahedron , delocalized electron , metastability , covalent bond , materials science , biochemistry , organic chemistry , catalysis
Abstract Bi 2 Pt( hP 9) or γ‐Bi 2 Pt is a high‐temperature modification, which is metastable below 420 °C. We obtained Bi 2 Pt( hP 9) by reducing the layered bismuth subiodide Bi 13 Pt 3 I 7 with a high excess of n ‐butyllithium at 70 °C. The crystals endure the heterogeneous reaction and the enormous mass loss. X‐ray diffraction on a small single‐crystal revealed that Bi 2 Pt( hP 9) crystallizes in the acentric trigonal space group P 31 m (no. 157) with a = 657.30(7) pm and c = 616.65(7) pm. Although structure and stacking of the layers of edge‐sharing [PtBi 6/3 ] octahedra resemble the 1H‐polytype of CdI 2 , Pt–Pt bonding interactions cause distortions that introduce polarity to the structure. Quantum chemical calculations followed by real‐space bonding analysis reveal polar covalent bonding between bismuth and platinum atoms that is not limited to nearest neighbor atoms but is essentially delocalized. The Pt–Pt bond strength in Bi 2 Pt( hP 9) is not much weaker than in the element.