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Title: Tunable trimers: Using temperature and pressure to control luminescent emission in gold(I) pyrazolate-based trimers

A systematic investigation into the relationship between the solid-state luminescence and the intermolecular Au∙∙∙Au interactions in a series of pyrazolate-based gold(I) trimers; tris(μ2-pyrazolato-N,N')-tri-gold(I) (1), tris(μ2-3,4,5-trimethylpyrazolato-N,N')-tri-gold(I) (2), tris(μ2-3-methyl-5-phenylpyrazolato-N,N')-tri-gold(I) (3) and tris(μ2-3,5-diphenylpyrazolato-N,N')-tri-gold(I) (4) has been carried out using variable temperature and high pressure X-ray crystallography, solid-state emission spectroscopy, Raman spectroscopy and computational techniques. Single-crystal X-ray studies show that there is a significant reduction in the intertrimer Au∙∙∙Au distances both with decreasing temperature and increasing pressure. In the four complexes, the reduction in temperature from 293 to 100 K is accompanied by a reduction in the shortest intermolecular Au∙∙∙Au contacts of between 0.04 and 0.08 Å. The solid-state luminescent emission spectra of 1 and 2 display a red shift with decreasing temperature or increasing pressure. Compound 3 does not emit under ambient conditions but displays increasingly red-shifted luminescence upon cooling or compression. Compound 4 remains emissionless, consistent with the absence of intermolecular Au∙∙∙Au interactions. The largest pressure induced shift in emission is observed in 2 with a red shift of approximately 630 cm-1 per GPa between ambient and 3.80 GPa. The shifts in all the complexes can be correlated with changes in Au∙∙∙Au distance observed by diffraction.
Authors:
 [1] ;  [1] ;  [2] ;  [1] ;  [1] ;  [1] ;  [1] ;  [2] ;  [3] ;  [3] ;  [3] ;  [3] ;  [1] ;  [1] ;  [1] ;  [1]
  1. Univ. of Bath, Bath (United Kingdom). Dept. of Chemistry.
  2. Lawrence Berkeley National Lab., CA (United States). Advanced Light Source.
  3. Universite de Montreal, Montreal, QC (Canada). Departement de Chimie.
Publication Date:
OSTI Identifier:
1213528
Grant/Contract Number:
AC02-05CH11231
Type:
Accepted Manuscript
Journal Name:
Chemistry - A European Journal
Additional Journal Information:
Journal Volume: 20; Journal Issue: 51; Journal ID: ISSN 0947-6539
Publisher:
ChemPubSoc Europe
Research Org:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS aurophilicity; crystallography; gold; high pressure; luminescence