Gilded Chalices: Tetra-aurated Calix[4]arenes

2014 ◽  
Vol 69 (11-12) ◽  
pp. 1061-1072 ◽  
Author(s):  
Ulf H. Strasser ◽  
Beate Neumann ◽  
Hans-Georg Stammler ◽  
Raphael J. F. Berger ◽  
Norbert W. Mitzela

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 (K2CO3) 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-Tol3PAuCl, Ph3PAuCl, Ph2MePAuCl, PhMe2PAuCl, Me3PAuCl, Cy3PAuCl, t-Bu3PAuCl) to afford in good to excellent yields the tetra-aurated tetraethynylcalix[4]arene species 3-9 in one step [with phosphane ligands o-Tol3P (3), Ph3P (4), Ph2MeP (5), PhMe2P (6), Me3P (7), Cy3P (8), t-Bu3P (9)]. All compounds were characterised by 1H NMR and infrared spectroscopy, mass spectrometry and by elemental analyses, additionally 3, 4, 5, 8 and 9 by 13C{1H}, and 3-6, 8 and 9 by 31P{1H} 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 (PH3) on the basis of quantum-chemical calculations; the energy of formation is 9:6 kJ mol-1. The crystal structure of Ph2MePAuCl was also determined and shows Au···Au-bonded dimers.

2007 ◽  
Vol 62 (3) ◽  
pp. 475-482 ◽  
Author(s):  
Karsten Schubert ◽  
Helmar Görls ◽  
Wolfgang Weigand

Starting from 4-bromoacetophenone 1, the 4-bromo-β -hydroxydithiocinnamic acid 2 and the 4-bromo-β -hydroxydithiocinnamic acid hexyl ester 3 were prepared using carbon disulfide and potassium-tert-butylate as a base. Acting as a ligand, the acid gives 1,1-ethenedithiolato complexes with (Ph3P)2Pt(II) (4a), (Et3P)2Pt(II) (4b), dppePt(II) (4c), (Ph3P)2Pd(II) (4d), dppePd(II) (4e), and dppeNi(II) (4f). In contrast to the acid, the deprotonated ester 3 forms a monoanionic bidentate ligand. [O,S] Complexes of Pt(II) (5a), Pd(II) (5b) and Ni(II) (5c) were obtained. All complexes have been fully characterised using 1H NMR, 13C NMR and 31P NMR spectroscopy, mass spectrometry, infrared spectroscopy and elemental analyses. The molecular structures of the complexes 4b and 5a - 5c were determined by X-ray diffraction analyses.


2016 ◽  
Vol 71 (12) ◽  
pp. 1269-1277 ◽  
Author(s):  
Elnaz Hobbollahi ◽  
Barbora Veselkova ◽  
Manuela List ◽  
Günther Redhammer ◽  
Uwe Monkowius

AbstractZn(II) halide complexes of the form L2ZnX2 (X=Cl, Br, I) containing bio-relevant or bio-related ligands like 1-alkyl-imidazoles (alkyl=methyl, ethyl and iso-propyl) or (–)-nicotine are presented. All complexes were characterized by 1H NMR spectroscopy, mass spectrometry and elemental analysis. The molecular structures of the majority of complexes were determined by single crystal X-ray diffraction. The zinc ion exists in a tetrahedral environment coordinated by two halide anions and two nitrogen atoms of the N-heterocycles. Upon photoexcitation the nicotine complexes feature a blue emission which we tentatively assign to phosphorescence.


2003 ◽  
Vol 58 (5) ◽  
pp. 389-394 ◽  
Author(s):  
Alexander A. Trifonov ◽  
Mikhail N. Bochkarev ◽  
Herbert Schumann ◽  
Sebastian Dechert

Racemic trans-2-(9(H)-fluoren-9-yl)cyclohexanol, C13H9-cyclo-C6H10-OH (1), reacts with two equivalents of potassium naphthalenide in THF to give the dipotassium salt [C13H8-cyclo-C6H10-O]- K2(THF) (2). Recrystallization of 2 from pyridine affords the solvent free salt [C13H8-cyclo-C6H10- O]K2 (3). The reactions of LaI3(THF)4 with one equivalent of 2 or of YbI2(THF)2 with equimolar amounts of 2 produce the alkoxolanthanum diiodide (C13H9-cyclo-C6H10-O)LaI2(DME)2 (4) and the ytterbium dialkoxide (C13H9-cyclo-C6H10-O)2Yb(THF)0.5(5), respectively. [(Me3Si)2N]3Y reacts with three equivalents of 1 with elimination of hexamethyldisilazane and formation of the yttrium trialkoxide (C13H9-cyclo-C6H10-O)3Y (6). The compounds 2 to 5 were characterized by elemental analyses, 1H NMR, 13C NMR and IR spectra. The molecular structure of 4 was determined by single crystal X-ray diffraction.


1991 ◽  
Vol 46 (6) ◽  
pp. 767-774 ◽  
Author(s):  
Pilar Souza ◽  
Luisa Sanz ◽  
Vicente Fernández ◽  
Agueda Arquero ◽  
Enrique Gutierrez ◽  
...  

Zinc, cadmiun and mercury dihalide react with 4-acetylpyridinthiosemicarbazone (4-aptsc) to give complexes with 1:1 and 2:1 ligand/metal stoichiometric ratios. These metals are effective templates for the Schiff-base condensation of 4-acetylpyridine with semicarbazide to give the complexes [M(4-apsc)X2] and [M(4-apsc)2X2] where M = Zn, Cd or Hg and X = Cl, Br or I. These compounds were characterized by elemental analyses, conductivities measurements, IR and 13C, 1H NMR spectra.The zinc chloride and bromide complexes of benzalthiosemicarbazone (btsc) have been prepared and characterized by X-ray measurements.The compounds Zn(btsc)2Cl2 and Cd(btsc)2Br2 are isostructural and crystallize in the space group P21/n. The crystal structure of the chlorine derivative has been resolved by single-crystal X-ray diffraction. The zinc centre is in a slightly distorted tetrahedral environment. There are intra and intermolecular hydrogen bonds.


1985 ◽  
Vol 63 (6) ◽  
pp. 1166-1169 ◽  
Author(s):  
John F. Richardson ◽  
Ted S. Sorensen

The molecular structures of exo-7-methylbicyclo[3.3.1]nonan-3-one, 3, and the endo-7-methyl isomer, 4, have been determined using X-ray-diffraction techniques. Compound 3 crystallizes in the space group [Formula: see text] with a = 15.115(1), c = 7.677(2) Å, and Z = 8 while 4 crystallizes in the space group P21 with a = 6.446(1), b = 7.831(1), c = 8.414(2) Å, β = 94.42(2)°, and Z = 2. The structures were solved by direct methods and refined to final agreement factors of R = 0.041 and R = 0.034 for 3 and 4 respectively. Compound 3 exists in a chair–chair conformation and there is no significant flattening of the chair rings. However, in 4, the non-ketone ring is forced into a boat conformation. These results are significant in interpreting what conformations may be present in the related sp2-hybridized carbocations.


Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 149-163
Author(s):  
Duncan Micallef ◽  
Liana Vella-Zarb ◽  
Ulrich Baisch

N,N′,N″,N‴-Tetraisopropylpyrophosphoramide 1 is a pyrophosphoramide with documented butyrylcholinesterase inhibition, a property shared with the more widely studied octamethylphosphoramide (Schradan). Unlike Schradan, 1 is a solid at room temperature making it one of a few known pyrophosphoramide solids. The crystal structure of 1 was determined by single-crystal X-ray diffraction and compared with that of other previously described solid pyrophosphoramides. The pyrophosphoramide discussed in this study was synthesised by reacting iso-propyl amine with pyrophosphoryl tetrachloride under anhydrous conditions. A unique supramolecular motif was observed when compared with previously published pyrophosphoramide structures having two different intermolecular hydrogen bonding synthons. Furthermore, the potential of a wider variety of supramolecular structures in which similar pyrophosphoramides can crystallise was recognised. Proton (1H) and Phosphorus 31 (31P) Nuclear Magnetic Resonance (NMR) spectroscopy, infrared (IR) spectroscopy, mass spectrometry (MS) were carried out to complete the analysis of the compound.


2020 ◽  
Vol 235 (8-9) ◽  
pp. 311-317
Author(s):  
Stephan G. Jantz ◽  
Florian Pielnhofer ◽  
Henning A. Höppe

Abstract${\text{Pb}}_{5}{\text{O}}_{2}\left[{\text{WO}}_{6}\right]$ was discovered as a frequently observed side phase during our investigation on lead tungstates. Its crystal structure was solved by single-crystal X-ray diffraction ($P{2}_{1}/n$, $a=7.4379\left(2\right)$ Å, $b=12.1115\left(4\right)$ Å, $c=10.6171\left(3\right)$ Å, $\beta =90.6847\left(8\right)$°, $Z=4$, ${R}_{\text{int}}=0.038$, ${R}_{1}=0.020$, $\omega {R}_{2}=0.029$, 4188 data, 128 param.) and is isotypic with ${\text{Pb}}_{5}{\text{O}}_{2}\left[{\text{Te}}_{6}\right]$. ${\text{Pb}}_{5}{\text{O}}_{2}\left[{\text{WO}}_{6}\right]$ comprises a layered structure built up by non-condensed [WO6]${}^{6-}$ octahedra and ${\left[{\text{O}}_{4}{\text{Pb}}_{10}\right]}^{12+}$ oligomers. The compound was characterised by spectroscopic measurements (Infrared (IR), Raman and Ultraviolet–visible (UV/Vis) spectra) as well as quantum chemical and electrostatic calculations (density functional theory (DFT), MAPLE) yielding a band gap of 2.9 eV fitting well with the optical one of 2.8 eV. An estimation of the refractive index based on the Gladstone-Dale relationship yielded $n\approx 2.31$. Furthermore first results of the thermal analysis are presented.


2013 ◽  
Vol 803 ◽  
pp. 80-84
Author(s):  
Yu Qi Liu ◽  
Yong Yang ◽  
Rui Yang ◽  
Xiao Jun Xu

A novel metalorganic coordination polymer, namely [Co3(bpd)5.5(NCS)6(NH3)]n2H2O (1) (bpd=1,4-bis (4-pyridyl)-2,3-diaza-1,3-butadiene), has been synthesized and characterized by elemental analyses, infrared spectroscopy, and single-crystal X-ray diffraction. Compound 1 presents 2D[3,4,-connected 3-nodal net with the point symbol (4268210)(4462)(8210). In addition, four identical 2D single nets is interlocked with each other in parallel, thus directly leading to the formation of a polycatenated layer (2D2D).


2009 ◽  
Vol 2009 (7) ◽  
pp. 437-439 ◽  
Author(s):  
Sara Tarighi ◽  
Alireza Abbasi ◽  
Sara Zamanian ◽  
Alireza Badiei ◽  
Mahmood Ghoranneviss

3-Chlorobenzo[b]thiophene-2-carbonyl chloride was synthesised from cinnamic acid and thionyl chloride. The single crystal X-ray structure determination confirmed the earlier proposed structure and the product was further characterised by 1H NMR, 13C NMR and mass spectrometry. The X-ray structure determination revealed two sets of symmetry related molecules along the b-axis that are loosely connected by relatively weak CH…π ( 3.626, 3.628 Å) interactions, giving rise to two infinite chains. The packing structure is dominated by Van der Waals forces between these chains. No significant π–π interactions are found in the crystal structure.


1983 ◽  
Vol 38 (2) ◽  
pp. 190-193 ◽  
Author(s):  
Reinhold Tacke ◽  
Hartwig Lange ◽  
Anke Bentlage ◽  
William S. Sheldrick ◽  
Ludger Ernst

Abstract The 2,2,5,5-tetraorganyl-1,4-dioxa-2,5-disilacyclohexanes 2a-2c were prepared by condensation of the corresponding (hydroxymethyl)diorganylsilanes 1 a-1 c. The constitution of the heterocycles was confirmed by elemental analyses, cryoscopic measurements, mass spectrometry, and NMR-spectroscopic (1H, 13C) investigations. The molecular structure of 2 b was determined by X-ray diffraction analysis.


Sign in / Sign up

Export Citation Format

Share Document