In:
Zeitschrift für Naturforschung B, Walter de Gruyter GmbH, Vol. 69, No. 11-12 ( 2014-12-1), p. 1061-1072
Abstract:
5,11,17,23-Tetrakis(trimethylsilylethynyl)-25,26,27,28-tetra-n-propoxycalix[4]arene (1) was synthesised in two steps starting from 25,26,27,28-tetra-n-propoxycalix[4] arene, and the structure of 1 was determined by X-ray diffraction. Compound 1 was desilylated (K 2 CO 3 ) to give 5,11,17,23- tetrakis(ethynyl)-25,26,27,28-tetra-n-propoxycalix[4]arene (2), which was tetra-aurated under basic conditions (NaOEt, THF) with a series of phosphane-gold chlorides (o-Tol 3 PAuCl, Ph 3 PAuCl, Ph 2 MePAuCl, PhMe 2 PAuCl, Me 3 PAuCl, Cy 3 PAuCl, t-Bu 3 PAuCl) to afford in good to excellent yields the tetra-aurated tetraethynylcalix[4]arene species 3-9 in one step [with phosphane ligands o-Tol 3 P (3), Ph 3 P (4), Ph 2 MeP (5), PhMe 2 P (6), Me 3 P (7), Cy 3 P (8), t-Bu 3 P (9)]. All compounds were characterised by 1 H NMR and infrared spectroscopy, mass spectrometry and by elemental analyses, additionally 3, 4, 5, 8 and 9 by 13 C{ 1 H}, and 3-6, 8 and 9 by 31 P{ 1 H} NMR spectroscopy. The molecular structures of complexes 3 and 9 were determined by X-ray diffraction and show pinched-cone conformations, but neither intra- nor intermolecular attractive aurophilic Au···Au contacts. The acceptor ability of complexes 3 and 9 was investigated by complexation attempts with various phosphane-gold chlorides and xenon gas under pressure, but interactions could not be determined experimentally. The formation of a complex between xenon and gilded calix[4]arene could, however, be predicted for fluorine-substituted species and with very small phosphane ligands (PH 3 ) on the basis of quantum-chemical calculations; the energy of formation is 9:6 kJ mol -1 . The crystal structure of Ph 2 MePAuCl was also determined and shows Au···Au-bonded dimers.
Type of Medium:
Online Resource
ISSN:
1865-7117
,
0932-0776
DOI:
10.5560/znb.2014-4149
Language:
English
Publisher:
Walter de Gruyter GmbH
Publication Date:
2014
detail.hit.zdb_id:
2078109-X
detail.hit.zdb_id:
124635-5
