Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Synthesis and structural characterization of tris(2-mercapto-1-methylbenzimidazolyl)hydroborato cadmium halide complexes, {[Tm(MeBenz)]Cd(?-Cl)}2 and [Tm(MeBenz)]CdI: a rare example of cadmium in a trigonal bipyramidal sulfur-rich coordination environment.

ABSTRACT: The tris(2-mercapto-1-methylbenzimidazolyl)hydroborato cadmium complexes, {[Tm(MeBenz)]Cd(?-Cl)}2 and [Tm(MeBenz)]CdI, have been synthesized via the reactions of [Tm(MeBenz)]K with CdCl2 and CdI2, respectively. While X-ray diffraction studies demonstrate that the iodide derivative, [Tm(MeBenz)]CdI, is a monomer, the chloride derivative, {[Tm(MeBenz)]Cd(?-Cl)}2, exists as a dimer, which is unprecedented for Group 12 [Tm(R)]MX (X = Cl, Br, I) compounds. Furthermore, the cadmium centers of {[Tm(MeBenz)]Cd(?-Cl)}2 are trigonal bipyramidal, which is an uncommon motif for cadmium complexes with a [S3Cl2] coordination sphere.

SUBMITTER: Palmer JH

PROVIDER: S-EPMC4262141 | biostudies-literature | 2014 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Synthesis and structural characterization of tris(2-mercapto-1-methylbenzimidazolyl)hydroborato cadmium halide complexes, {[Tm(MeBenz)]Cd(μ-Cl)}2 and [Tm(MeBenz)]CdI: a rare example of cadmium in a trigonal bipyramidal sulfur-rich coordination environment.

Palmer Joshua H JH Parkin Gerard G

Dalton transactions (Cambridge, England : 2003) 20140808 37

The tris(2-mercapto-1-methylbenzimidazolyl)hydroborato cadmium complexes, {[Tm(MeBenz)]Cd(μ-Cl)}2 and [Tm(MeBenz)]CdI, have been synthesized via the reactions of [Tm(MeBenz)]K with CdCl2 and CdI2, respectively. While X-ray diffraction studies demonstrate that the iodide derivative, [Tm(MeBenz)]CdI, is a monomer, the chloride derivative, {[Tm(MeBenz)]Cd(μ-Cl)}2, exists as a dimer, which is unprecedented for Group 12 [Tm(R)]MX (X = Cl, Br, I) compounds. Furthermore, the cadmium centers of {[Tm(MeB ...[more]

PMID: 25105778

Similar Datasets

Synthesis and structures of cadmium carboxylate and thiocarboxylate compounds with a sulfur-rich coordination environment: carboxylate exchange kinetics involving tris(2-mercapto-1-t-butylimidazolyl)hydroborato cadmium complexes, [Tm(Bu(t))]Cd(O2CR).

Project description:A series of cadmium carboxylate compounds in a sulfur-rich environment provided by the tris(2-tert-butylmercaptoimidazolyl)hydroborato ligand, namely, [Tm(Bu(t))]CdO2CR, has been synthesized via the reactions of the cadmium methyl derivative [Tm(Bu(t))]CdMe with RCO2H. Such compounds mimic aspects of cadmium-substituted zinc enzymes and also the surface atoms of cadmium chalcogenide crystals, and have therefore been employed to model relevant ligand exchange processes. Significantly, both (1)H and (19)F NMR spectroscopy demonstrate that the exchange of carboxylate groups between [Tm(Bu(t))]Cd(?(2)-O2CR) and the carboxylic acid RCO2H is facile on the NMR time scale, even at low temperature. Analysis of the rate of exchange as a function of concentration of RCO2H indicates that reaction occurs via an associative rather than dissociative pathway. In addition to carboxylate compounds, the thiocarboxylate derivative [Tm(Bu(t))]Cd[?(1)-SC(O)Ph] has also been synthesized via the reaction of [Tm(Bu(t))]CdMe with thiobenzoic acid. The molecular structure of [Tm(Bu(t))]Cd[?(1)-SC(O)Ph] has been determined by X-ray diffraction, and an interesting feature is that, in contrast to the carboxylate derivatives [Tm(Bu(t))]Cd(?(2)-O2CR), the thiocarboxylate ligand binds in a ?(1) manner via only the sulfur atom.

| S-EPMC4415050 | biostudies-literature

Influence of Benzannulation on Metal Coordination Geometries: Synthesis and Structural Characterization of Tris(2-mercapto-1-methylbenzimidazolyl)hydroborato Cadmium Bromide, {[TmMeBenz]Cd(μ-Br)}2.

Project description:The tris(2-mercapto-1-methylbenzimidazolyl)hydroborato cadmium complex, {[TmMeBenz]Cd(μ-Br)}2, may be synthesized via the reaction of [TmMeBenz]K with CdBr2. X-ray diffraction demonstrates that {[TmMeBenz]Cd(μ-Br)}2 exists as a dimer, which is in marked contrast to the monomeric structure of the non-benzannulated counterpart, [TmMe]CdBr, and thereby demonstrates that benzannulation of tris(2-mercapto-1-methylbenzimidazolyl)hydroborato ligands can have a distinct impact on the molecular structure of their metal complexes. In accord with this observation, density functional theory calculations indicate that the benzannulated dimers, {[TmMeBenz]Cd(μ-X)}2 (X = Cl, Br, I), are more stable with respect to dissociation than are their non-benzannulated counterparts, {[TmMe]Cd(μ-X)}2. Furthermore, the calculations also indicate that the stability of the dimer depends on the nature of X, such that the dimer becomes more stable in the sequence I < Br < Cl.

| S-EPMC4296741 | biostudies-literature

Synthesis, structure, and physical properties for a series of trigonal bipyramidal M(II)-Cl complexes with intramolecular hydrogen bonds.

Project description:A series of transition metal chloro complexes with the tetradentate tripodal tris(2-amino-oxazoline)amine ligand (TAO) have been synthesized and characterized. X-Ray structural analyses of these compounds demonstrate the formation of the mononuclear complexes [M(II)(TAO)(Cl)](+), where M(II) = Cr, Mn, Fe, Co, Ni, Cu and Zn. These complexes exhibit distorted trigonal-bipyramidal geometry, coordinating the metal through an apical tertiary amine, three equatorial imino nitrogen atoms, and an axial chloride anion. All the complexes possess an intramolecular hydrogen-bonding (H-bonding) network within the cavity occupied by the metal-bound chloride ion. The metal-chloride bond distances are atypically long, which is attributed to the effects of the H-bonding network. Nuclear magnetic resonance (NMR) spectroscopy of the Zn complex suggests that the solid-state structures are representative of that observed in solution, and that the H-bonding interactions persist as well. Additionally, density functional theory (DFT) calculations were carried out to probe the electronic structures of the complexes.

| S-EPMC3777263 | biostudies-literature

Tris(2-mercaptoimidazolyl)hydroborato Cadmium Thiolate Complexes, [TmBut]CdSAr: Thiolate Exchange at Cadmium in a Sulfur-Rich Coordination Environment.

Project description:A series of cadmium thiolate compounds that feature a sulfur-rich coordination environment, namely [TmBut]CdSAr, have been synthesized by the reactions of [TmBut]CdMe with ArSH (Ar = C6H4-4-F, C6H4-4-But, C6H4-4-OMe, and C6H4-3-OMe). In addition, the pyridine-2-thiolate and pyridine-2-selenolate derivatives, [TmBut]CdSPy and [TmBut]CdSePy have been obtained via the respective reactions of [TmBut]CdMe with pyridine-2-thione and pyridine-2-selone. The molecular structures of [TmBut]CdSAr and [TmBut]CdEPy (E = S or Se) have been determined by X-ray diffraction and demonstrate that, in each case, the [CdS4] motif is distorted tetrahedral and approaches a trigonal monopyramidal geometry in which the thiolate ligand adopts an equatorial position; [TmBut]CdSPy and [TmBut]CdSePy, however, exhibit an additional long-range interaction with the pyridyl nitrogen atoms. The ability of the thiolate ligands to participate in exchange was probed by 1H and 19F nuclear magnetic resonance (NMR) spectroscopic studies of the reactions of [TmBut]CdSC6H4-4-F with ArSH (Ar = C6H4-4-But or C6H4-4-OMe), which demonstrate that (i) exchange is facile and (ii) coordination of thiolate to cadmium is most favored for the p-fluorophenyl derivative. Furthermore, a two-dimensional EXSY experiment involving [TmBut]CdSC6H4-4-F and 4-fluorothiophenol demonstrates that degenerate thiolate ligand exchange is also facile on the NMR time scale.

| S-EPMC5461919 | biostudies-literature

Pushing the limits of magnetic anisotropy in trigonal bipyramidal Ni(ii).

Project description:Monometallic complexes based on 3d transition metal ions in certain axial coordination environments can exhibit appreciably enhanced magnetic anisotropy, important for memory applications, due to stabilisation of an unquenched orbital moment. For high-spin trigonal bipyramidal Ni(ii), if competing structural distortions can be minimised, this may result in an axial anisotropy that is at least an order of magnitude stronger than found for orbitally non-degenerate octahedral complexes. Broadband, high-field EPR studies of [Ni(MDABCO)2Cl3]ClO4 (1) confirm an unprecedented axial magnetic anisotropy, which pushes the limits of the familiar spin-only description. Crucially, compared to complexes with multidentate ligands that encapsulate the metal ion, we see only a very small degree of axial symmetry breaking. 1 displays field-induced slow magnetic relaxation, which is rare for monometallic Ni(ii) complexes due to efficient spin-lattice and quantum tunnelling relaxation pathways.

| S-EPMC5508675 | biostudies-literature

Synthesis and characterization of trigonal bipyramidal FeIII complexes and their solution behavior.

Project description:A series of air-stable trigonal bipyramidal FeIII complexes supported by a redox non-innocent NNN pincer ligand, Cz tBu(PyrR)2- (R = iPr, Me, or H), were synthesized, fully characterized, and utilized for the investigation of the interaction between acetone and the FeIII center. The magnetic moments determined from the paramagnetic 1H NMR spectra in conjunction with EPR and Mössbauer spectroscopy indicate the presence of a high-spin ferric center. Cyclic voltammetry studies feature two quasi-reversible events corresponding to a metal-centered FeIII/II reduction around -0.40 V (vs. Fc) and a ligand-centered Cz tBu(PyrR)2/Cz tBu(PyrR)2•+ oxidation at potentials near +0.70 V (vs. Fc). UV-Visible spectroscopy in CH2Cl2 showcases ligand-metal charge transfer (LMCT) bands, as well as coordination of acetone to Cz tBu(PyrH)2FeCl2. In situ IR spectroscopy and solution conductivity (κ) measurements of Cz tBu(PyrR)2FeCl2 with varied equivalents of acetone reveal that acetone is weakly associated with the iron center.

| S-EPMC8462799 | biostudies-literature

Bidentate Zinc chelators for alpha-carbonic anhydrases that produce a trigonal bipyramidal coordination geometry.

Project description:A series of new zinc binding groups (ZBGs) has been evaluated kinetically on 13 carbonic anhydrase (CA) isoforms. The fragments show affinity for all isoforms with IC(50) values in the range of 2-11 microM. The crystal structure of hCA II in complex with one such fragment reveals a bidentate binding mode with a trigonal-bipyramidal coordination geometry at the Zn(2+) center. The fragment also interacts with Thr199 and Thr200 through hydrogen bonding and participates in a water network. Further development of this ZBG should increase the binding affinity leading to a structurally distinct and promising class of CA inhibitors.

| S-EPMC3019337 | biostudies-literature

A more reactive trigonal-bipyramidal high-spin oxoiron(IV) complex with a cis-labile site.

Project description:The trigonal-bipyramidal high-spin (S = 2) oxoiron(IV) complex [Fe(IV)(O)(TMG(2)dien)(CH(3)CN)](2+) (7) was synthesized and spectroscopically characterized. Substitution of the CH(3)CN ligand by anions, demonstrated here for X = N(3)(-) and Cl(-), yielded additional S = 2 oxoiron(IV) complexes of general formulation [Fe(IV)(O)(TMG(2)dien)(X)](+) (7-X). The reduced steric bulk of 7 relative to the published S = 2 complex [Fe(IV)(O)(TMG(3)tren)](2+) (2) was reflected by enhanced rates of intermolecular substrate oxidation.

| S-EPMC3150404 | biostudies-literature

[MIII2MII3] n+ trigonal bipyramidal cages based on diamagnetic and paramagnetic metalloligands.

Project description:A family of five [MIII2MII3] n+ trigonal bipyramidal cages (MIII = Fe, Cr and Al; MII = Co, Zn and Pd; n = 0 for 1-3 and n = 6 for 4-5) of formulae [Fe2Co3L6Cl6] (1), [Fe2Zn3L6Br6] (2), [Cr2Zn3L6Br6] (3), [Cr2Pd3L6(dppp)3](OTf)6 (4) and [Al2Pd3L6(dppp)3](OTf)6 (5) (where HL is 1-(4-pyridyl)butane-1,3-dione and dppp is 1,3-bis(diphenylphosphino)propane) are reported. Neutral cages 1-3 were synthesised using the tritopic [MIIIL3] metalloligand in combination with the salts CoIICl2 and ZnIIBr2, which both act as tetrahedral linkers. The assembly of the cis-protected [PdII(dppp)(OTf)2] with [MIIIL3] afforded the anionic cages 4-5 of general formula [MIII2PdII3](OTf)6. The metallic skeleton of all cages describes a trigonal bipyramid with the MIII ions occupying the two axial sites and the MII ions sitting in the three equatorial positions. Direct current (DC) magnetic susceptibility, magnetisation and heat capacity measurements on 1 reveal weak antiferromagnetic exchange between the FeIII and CoII ions. EPR spectroscopy demonstrates that the distortion imposed on the {MO6} coordination sphere of [MIIIL3] by complexation in the {MIII2MII3} supramolecules results in a small, but measurable, increase of the zero field splitting at MIII. Complete active space self-consistent field (CASSCF) calculations on the three unique CoII sites of 1 suggest DCo ≈ -14 cm-1 and E/D ≈ 0.1, consistent with the magnetothermal and spectroscopic data.

| S-EPMC5618769 | biostudies-literature

Probing the origin of the giant magnetic anisotropy in trigonal bipyramidal Ni(ii) under high pressure.

Project description:Understanding and controlling magnetic anisotropy at the level of a single metal ion is vital if the miniaturisation of data storage is to continue to evolve into transformative technologies. Magnetic anisotropy is essential for a molecule-based magnetic memory as it pins the magnetic moment of a metal ion along the easy axis. Devices will require deposition of magnetic molecules on surfaces, where changes in molecular structure can significantly alter magnetic properties. Furthermore, if we are to use coordination complexes with high magnetic anisotropy as building blocks for larger systems we need to know how magnetic anisotropy is affected by structural distortions. Here we study a trigonal bipyramidal nickel(ii) complex where a giant magnetic anisotropy of several hundred wavenumbers can be engineered. By using high pressure, we show how the magnetic anisotropy is strongly influenced by small structural distortions. Using a combination of high pressure X-ray diffraction, ab initio methods and high pressure magnetic measurements, we find that hydrostatic pressure lowers both the trigonal symmetry and axial anisotropy, while increasing the rhombic anisotropy. The ligand-metal-ligand angles in the equatorial plane are found to play a crucial role in tuning the energy separation between the d x2-y2 and d xy orbitals, which is the determining factor that controls the magnitude of the axial anisotropy. These results demonstrate that the combination of high pressure techniques with ab initio studies is a powerful tool that gives a unique insight into the design of systems that show giant magnetic anisotropy.

| S-EPMC5890327 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data