Search results for " complex"
showing 10 items of 3391 documents
Crystal structure of a rare trigonal bipyramidal titanium(IV) coordination complex: trichlorido(3,3′-di-tert-butyl-2′-hydroxy-5,5′,6,6′-tetramethyl-1…
2017
The title compound, [Ti(C24H33O2)Cl3(C4H8O)], is a rare example of a trigonal–bipyramidal titanium coordination complex with three chloride and two oxygen donor ligands. The asymmetric unit contains two independent molecules having essentially the same conformation. The molecules feature the titanium(IV) metal cation complexed with three chloride ligands, a tetrahydrofuran molecule, and one oxygen atom from the resolved ligand precursor (R)-(+)-5,5′,6,6′-tetramethyl-3,3′-di-t-butyl-1,1′-biphenyl-2,2′-diol, where the remaining phenolic hydrogen atom engages in intermolecular O—H...Cl hydrogen bonding. In one molecule, the THF ligand is disordered over two orientations with refined site occup…
The avidin-theophylline complex: A structural and computational study
2023
: The interaction between avidin and its counterpart biotin is one of central importance in biology and has been reproposed and studied at length. However, the binding pocket of avidin is prone to promiscuous binding, able to accommodate even non-biotinylated ligands. Comprehending the factors that distinguish the extremely strong interaction with biotin to other ligands is an important step to fully picture the thermodynamics of these low-affinity complexes. Here, we present the complex between chicken white egg avidin and theophylline (TEP), the xanthine derivative used in the therapy of asthma. In the crystal structure, TEP lies in the biotin-binding pocket with the same orientation and …
Crystal structure of cis-bis(μ-β-alanine-κ2 O:O′)bis[trichloridorhenium(III)](Re–Re) sesquihydrate
2015
A dirhenium(III) cis-dicarboxylate complex is reported, which is representative of a small class of zwitterionic ammoniacarboxylato complexes involving a quadruple metal–metal bond.
Crystal structure of di-μ-isobutyrato-κ(4) O:O'-bis-[cis-di-chlorido-(dimethyl sulfoxide-κS)rhenium(III)].
2015
A binuclear bis(carboxylato)dirhenium(III) complex is reported. The compound is a representative of a small class of alkylcarboxylate complexes involving a quadruple metal–metal bonds
Crystal structure of chlorido(2-{[2-(4-chlorophenyl)hydrazin-1-ylidene-κN1](phenyl)methyl}pyridine-κN)(η5-pentamethylcyclopentadienyl)iridium(III) te…
2015
The title compound, [Ir(η5-C5Me5)Cl(C18H14ClN3)]B(C6H5)4, is chiral at the metal center and crystallizes as a racemate. In the cation, the hydrazinylidenepyridine ligand isN,N-coordinated through theN-pyridyl andN-hydrazinylidene groups forming a five-membered metallacycle. An intramolecular C—H...Cl hydrogen bond is observed. In the crystal, centrosymmetrically-related cations are connected by C—Cl...π interactions, forming a dimeric structure. The crystal packing is further stabilized by weak interionic C—H...π interactions.
Direct observation of a borane–silane complex involved in frustrated Lewis-pair-mediated hydrosilylations
2014
Perfluorarylborane Lewis acids catalyse the addition of silicon–hydrogen bonds across C=C, C=N and C=O double bonds. This ‘metal-free’ hydrosilylation has been proposed to occur via borane activation of the silane Si–H bond, rather than through classical Lewis acid/base adducts with the substrate. However, the key borane/silane adduct had not been observed experimentally. Here it is shown that the strongly Lewis acidic, antiaromatic 1,2,3-tris(pentafluorophenyl)-4,5,6,7-tetrafluoro-1-boraindene forms an observable, isolable adduct with triethylsilane. The equilibrium for adduct formation was studied quantitatively through variable-temperature NMR spectroscopic investigations. The interacti…
Crystal structure of tricarbonyl(μ-diphenylphosphido-κ2P:P)(methyldiphenylsilyl-κSi)bis(triphenylphosphane-κP)iron(II)platinum(0)(Fe—Pt)
2015
The title compound belongs to the large family of heterodinuclear phosphide-bridged complexes. The Fe—Pt bond is of 2.7738 (4) Å and there is an unprecedented arrangement of the silyl ligand in a trans-position with respect to the metal–metal vector in the family of phosphide-bridged iron–platinum heterobimetallics.
A second solvatomorph of poly[[μ4-N,N′-(1,3,5-oxadiazinane-3,5-diyl)bis(carbamoylmethanoato)]nickel(II)dipotassium] : crystal structure, Hirshfeld su…
2021
The title compound, poly[triaquabis[μ4-N,N′-(1,3,5-oxadiazinane-3,5-diyl)bis(carbamoylmethanoato)]dinickel(II)tetrapotassium], [K4Ni2(C7H6N4O7)2(H2O)3] n , is a second solvatomorph of poly[(μ4-N,N′-(1,3,5-oxadiazinane-3,5-diyl)bis(carbamoylmethanoato)nickel(II)dipotassium] reported previously [Plutenko et al. (2021). Acta Cryst. E77, 298–304]. The asymmetric unit of the title compound includes two structurally independent complex anions [Ni(C7H6N4O7)]2−, which exhibit an L-shaped geometry and consist of two almost flat fragments perpendicular to one another: the 1,3,5-oxadiazinane fragment and the fragment including other atoms of the anion. The central Ni atom is in a square-planar N2O2 co…
Crystal structure, spectroscopic characterization and Hirshfeld surface analysis of trans-diaqua[2,5-bis(pyridin-4-yl)-1,3,4-oxadiazole]dithioc…
2019
The NiII atom in the mononuclear title complex has an almost regular octahedral N4O2 coordination geometry. In the crystal, the complex molecules are linked in a three-dimensional network through strong O—H⋯N hydrogen bonds.
Preparation of potentially porous, chiral organometallic materials through spontaneous resolution of pincer palladium conformers.
2013
Understanding the mechanism by which advanced materials assemble is essential for the design of new materials with desired properties. Here, we report a method to form chiral, potentially porous materials through spontaneous resolution of conformers of a PCP pincer palladium complex ({2,6-bis[(di-t-butylphosphino)methyl]phenyl}palladium(II)halide). The crystallisation is controlled by weak hydrogen bonding giving rise to chiral qtz-nets and channel structures, as shown by 16 such crystal structures for X = Cl and Br with various solvents like pentane and bromobutane. The fourth ligand (in addition to the pincer ligand) on palladium plays a crucial role; the chloride and the bromide primaril…