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Preparation and Structure of Hexakis[(trialkylphosphane)aurio(I)]methanium(2+) Salts [(LAu) 6 C] 2+ (X ‐ ) 2 with LEt 3 P, i Pr 3 P and XBF 4 ‐ , B 3 O 3 F 4 ‐
Author(s) -
Schmidbaur Hubert,
Brachthäuser Benno,
Steigelmann Oliver,
Beruda Holger
Publication year - 1992
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19921251214
Subject(s) - chemistry , dication , crystallography , octahedron , crystal structure , atom (system on chip) , metal , carbon fibers , nuclear magnetic resonance spectroscopy , stereochemistry , ion , organic chemistry , materials science , composite number , computer science , embedded system , composite material
Hexaaurated carbon complexes of the type [(R 3 PAu) 6 C](BF 4 ) 2 , REt ( 2a ), i Pr ( 2b ) have been prepared by the reaction of the appropriate (phosphane)gold(I) chlorides R 3 PAuCl ( 1a and 1b ) with tetrakis(dimethoxyboryl)methane, 13 C–enriched at the central carbon atom, in the presence of excess of CsF in HMPT at room temperature. The products 2a and 2b are characterized by standard spectroscopic methods including direct detection of the interstitial C atoms by 13 C–NMR spectroscopy. The crystal structure of the compound [( i Pr 3 PAu) 6 C](B 3 O 3 F 4 ) 2 · 3 CH 2 Cl 2 ( 3 ), obtained from partial (anion) hydrolysis has been determined. It contains dications with a central carbon atom surrounded by six (phosphane)gold(I) units. The edges of the CAu 6 octahedron represent short Au–Au contacts (aprox. 3.0 Å), which strongly contribute to the formation and stability of these hypercoordinated species. Attempts to prepare a corresponding hexaauriomethanium dication starting from t Bu 3 PAuCl ( 1c ) failed owing to the bulkiness of the (tri‐ tert ‐butylphosphane)gold(I) unit. The X–ray structure analysis for 1c verifies an extremely crowded environment of the gold atom with small Au—P—C angles of only 107° leading to efficient shielding of the metal atom by methyl groups.