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Title: Structure and Luminescence Studies of Salts of the Helical Dication, [Au 2 (μ-bis(diphenylphosphine)ethane) 2 ] 2+ and Comparison with Salts of [Au 2 (μ-bis(diphenylphosphine)propane) 2 ] 2+
Six salts ([Au2(μ-dppe)2](BF4)2·CHCl3, [Au2(μ- dppe)2](BF4)2·1,2-Cl2C2H4, [Au2(μ-dppe)2](PF6)2·CHCl3, [Au2(μ-dppe)2](PF6)2, [Au2(μ-dppe)2](SbF6)2, and [Au2(μ- dppe)2](OTf)2·2CHCl3), (dppe is bis(diphenylphosphine)ethane) containing the dication, [Au2(μ-dppe)2]2+, have been prepared and structurally characterized by single-crystal X-ray crystallography. Unlike the three-coordinate dppe-bridged dimers, Au2X2(μ-dppe)2 (X = Br, I), which show considerable variation in the distance between the gold(I) ions over the range 3.0995(10) to 3.8479(3) Å in various solvates, the structure of the helical dication, [Au2(μ- dppe)2], in the new salts is remarkably consistent with the Au···Au separation falling in the narrow range 2.8787(9) to 2.9593(5) Å. In the solid state, the six crystals display a green luminescence both at room temperature and at 77 K, which has been assigned as phosphorescence. However, solutions of the dication are not luminescent. Salts containing the analogous dication [Au2(μ-dppp)2](PF6)2 (dppp is bis(diphenylphosphine)propane) have been prepared to determine whether the longer bridging ligand might also twist into a helical shape. These salts include [Au2(μ- dppp)2](OTf)2 (OTf is triflate) and three crystalline forms of [Au2(μ-dppp)2](PF6)2: the solvate [Au2(μ-dppp)2](PF6)2·(CHCl3) and two polymorphs of the unsolvated salt. None of these crystals are luminescent, but all contain a similar dication, [Au2(μ- dppp)2]2+, that contains two nearly parallel, linear P−Au−P groups and a long separation between the gold ions that varies from 5.3409(4) to 5.6613(6)Å.  more » « less
Award ID(s):
1807637
PAR ID:
10525607
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
American Chemical Society
Date Published:
Journal Name:
Inorganic Chemistry
Volume:
62
Issue:
39
ISSN:
0020-1669
Page Range / eLocation ID:
15902 to 15911
Subject(s) / Keyword(s):
Gold Luminescence Helical Complex.
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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