Search results for "Solid-State"
showing 10 items of 530 documents
Preparation and structural studies on dibutyltin(IV) complexes with pyridine mono- and dicarboxylic acids
2004
Abstract A number of organotin(IV) complexes with pyridine mono- and dicarboxylic acids (containing ligating –COOH group(s) and aromatic {N} atoms) were prepared in the solid state. The bonding sites of the ligands were determined by means of FT-IR spectroscopic measurements. It was found that in most cases the –COO− groups form bridges between two central {Sn} atoms, thereby leading to polymeric (oligomeric) complexes. On this basis, the experimental 119Sn Mossbauer spectroscopic data were treated with partial quadrupole splitting approximations. The calculations predicted the existence of complexes with octahedral (oh) and trigonal-bipyramidal (tbp) structures, but the formation of comple…
Thermal behaviour and electrochemical properties of bis(trifluoromethanesulfonyl)amide and dodecatungstosilicate viologen dimers
2012
We report the synthesis and characterization of dimeric viologen salts (1',1''-(alkane-1,n-diyl)bis(1-ethyl-4,4'-bipyridinium) with n = 4-10) with bis(trifluoromethanesulfonyl)amide (bistriflimide, Tf(2)N(-)) as a counteranion. For n = 4, 5 and 6, and for the nonylviologen cation (1,1'-dinonyl-4,4'-bipyridinium) we also prepared salts with the totally inorganic dodecatungstosilicate anion, SiW(12)O(40)(4-), featuring a poly-charged surface and nanosized dimensions. The materials have been characterized by means of calorimetric techniques, X-ray diffraction and solid state NMR and a comparison is made with analogous monomeric viologen salts exhibiting smectic mesophases. A strong odd-even ef…
Folding and dimerization of resorcarene tetrasulfonates
2001
In the solid state and in CDCl3 resorcarene tetramesitylsulfonates fold by intramolecular SO⋯H–O hydrogen bonds and dimerise via intermolecular O–H⋯OH hydrogen bonding.
Intense laser effects on donor impurity in a cylindrical single and vertically coupled quantum dots under combined effects of hydrostatic pressure an…
2010
WOS: 000280235800010
Designing Solid Solutions of Enantiomers: Lack of Enantioselectivity of Chiral Naphthalimide Derivatives in the Solid State
2017
The enantiomers of a previously reported naphthalimide derivative are shown in this study to form a solid solution; furthermore, on the basis of the knowledge of solid solution structural aspects other naphthalimide derivatives have been synthesized and shown to lack the enantioselectivity in the solid state. The structural origin of solid solution formation is the same as observed in most of the cases in the literaturequasi-centrosymmetric structures form at nonracemic compositions where the most abundant enantiomer adjusts its conformation to mimic the absent one. Such solid solutions belong to the type showing some enantioselectivity. An extended single crystal X-ray diffraction study o…
Self-Assembly of a Copper(II)-Based Metallosupramolecular Hexagon
2008
The self-assembly of a 1:1 mixture of copper(II) ions and a rigid heteroditopic ligand L containing phen and terpy binding units gives rise in the solid state to green crystals of a hexanuclear metallamacrocycle 1. X-ray crystallography reveals that 1 consists of molecular hexagons of the grid-type family in which each metal ion is bound to two different ligands through the phen and terpy units, plus a weakly coordinated PF6 (-) anion in a highly distorted octahedral geometry. ES-MS studies of acetonitrile solutions of L and copper(II) in a 1:1 ratio show mixtures of polynuclear complexes in which trinuclear L3Cu3 species are predominant.
Sky-Blue Luminescent Au(I)-Ag(I) Alkynyl-Phosphine Clusters
2013
Treatment of the (AuC2R)n acetylides with phosphine ligand 1,4-bis(diphenylphosphino)butane (PbuP) and Ag(+) ions results in self-assembly of the heterobimetallic clusters of three structural types depending on the nature of the alkynyl group. The hexadecanuclear complex [Au12Ag4(C2R)12(PbuP)6](4+) (1) is formed for R = Ph, and the octanuclear species [Au6Ag2(C2R)6(PbuP)3](2+) adopting two structural arrangements in the solid state were found for the aliphatic alkynes (R = Bu(t) (2), 2-propanolyl (3), 1-cyclohexanolyl (4), diphenylmethanolyl (5), 2-borneolyl (6)). The structures of the compounds 1-4 and 6 were determined by single crystal X-ray diffraction analysis. The NMR spectroscopic st…
More insight into characterization of the waterlogged wooden part of Acqualadroni Roman Rostrum by solid-state NMR
2016
Abstract Solid-state NMR spectroscopy was applied to characterize the wooden part of a roman Rostrum recovered in the Tyrrhenian Sea in the Acqualadroni area (Messina, Italy). The Acqualadroni Rostrum has been, in the recent past, investigated to establish its provenance and conservation. In this paper, solid-state NMR was used to obtain information on the conservation state of the wood as a preliminary step for the conservation process. A wooden sample of this artifact, collected by coring, was divided in four parts in order to correlate the conservation state to the depth. Results were compared with those obtained for a modern wood of the same species. A structural study was performed by …
Formation, structure and reactivity of boryloxycarbyne complexes of group 6 metals.
2003
Reaction of the diborane(4) B(2)(NMe(2))(2)I(2) with two equivalents of K[(eta(5)-C(5)H(5))M(CO)(3)] (M=Cr, Mo, W) yielded the dinuclear boryloxycarbyne complexes [[(eta(5)-C(5)H(5))(OC)(2)M(triple bond)CO](2)B(2)(NMe(2))(2)] (4 a, M=Mo; b, M=W; c, M=Cr), which were fully characterised in solution by multinuclear NMR methods. The Mo and W complexes 4 a, b proved to be kinetically favoured products of this reaction and underwent quantitative rearrangement in solution to afford the complexes [[(eta(5)-C(5)H(5))(OC)(2)M(triple bond)CO]B(NMe(2))B(NMe(2))[M(CO)(3)(eta(5)-C(5)H(5))]] (5 a, M=Mo; b, M=W); 5 a was characterised by X-ray crystallography in the solid state. Corresponding reactions of…
Crystalline self-assembly induced by aromatic edge-to-face interactions: the crystal structure of 2,6,6,10-tetrabenzyl-2,10-diaza-6-azonia[11]paracyc…
2002
The crystal structure of 2,6,6,10-tetrabenzyl-2,10-diaza-6-azonia[11]paracyclophane bromide reveals several intermolecular aromatic edge-to-face interactions which are important in the three-dimensional growing of the crystalline structure. Molecular dynamics and semiempirical studies indicate that the conformer found in the crystal is not the most stable in solution confirming the important role that edge-to-face interactions play in the structural arrangement found in the solid state.