α-Diimine Cisplatin Derivatives: Synthesis, Structure, Cyclic Voltammetry and Cytotoxicity.

Three new Pt(II) complexes [(dpp-DAD)PtCl] (), [(Mes-DAD(Me))PtCl] () and [(dpp-DAD(Me))PtCl] () were synthesized by the direct reaction of [(CHCN)PtCl] and corresponding redox-active 1,4-diaza-1,3-butadienes (DAD). The compounds were isolated in a single crystal form and their molecular structures were determined by X-ray diffraction. The purity of the complexes and their stability in solution was confirmed by NMR analysis.

Sterically Hindered Tellurium(IV) Catecholate as a Lewis Acid.

Sterically hindered tellurium catecholate Te(Cat) (Cat = 3,6-di--butyl-catecholate) was synthesized with the reaction of amorphous Te with 3,6-di--butyl--benzoquinone. Adducts of Te(Cat) with various O- and N-donors were isolated and characterized by means of single-crystal X-ray diffraction along with IR, UV-vis, and NMR (H, C, and Te) spectroscopies. In the crystal structure of the adduct with 2,2'-bipyridine (bipy), the unprecedented μ-κ,':κ,'-bridging coordination mode of bipy was observed.

Simultaneous N polarization of several biocompatible substrates in ethanol-water mixtures by signal amplification by reversible exchange (SABRE) method.

Signal amplification by reversible exchange (SABRE) is a popular method for generating strong signal enhancements in nuclear magnetic resonance (NMR). In SABRE experiments, the source of polarization is provided by the nonthermal spin order of parahydrogen (pH , the H molecule in its nuclear singlet spin state). Polarization formation requires that both pH and a substrate molecule bind to an Ir-based complex where polarization transfer occurs.

Paramagnetic Rhenium Iodide Cluster with N-Heterocyclic Carbene.

-Trirhenium nonaiodide ReI reacts with 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes) to produce the novel 13-electron paramagnetic cluster ReI(IMes), which was characterized by means of X-ray diffraction analysis, ESR spectroscopy, magnetometry, and quantum chemistry.

A Sterically Hindered Derivative of 2,1,3-Benzotelluradiazole: A Way to the First Structurally Characterised Monomeric Tellurium-Nitrogen Radical Anion.

Interaction of the tetradentate redox-active 6,6'-[1,2-phenylenebis(azanediyl)]bis(2,4-di-tert-butylphenol) (H L) with TeCl leads to neutral diamagnetic compound TeL (1) in high yield. The molecule of 1 has a nearly planar TeN O fragment, which suggests the formulation of 1 as Te L , in agreement with the results of DFT calculations and QTAIM and NBO analyses. Reduction of 1 with one equivalent of [CoCp ] leads to quantitative formation of the paramagnetic salt [CoCp ] [1] , which was characterised by single-crystal XRD.

Nature of Bonding in Donor-Acceptor Interactions Exemplified by Complexes of N-Heterocyclic Carbenes with 1,2,5-Telluradiazoles.

Comprehensive structural, spectroscopic, and quantum chemical analyses of new donor-acceptor complexes between N-heterocyclic carbenes and 1,2,5-telluradiazoles and a comparison with previously known complexes involving tellurenyl cations showed that the dative C-Te bonds cannot be solitarily described with only one Lewis formula. Canonical Lewis formulas that denote covalency and arrows emphasizing ionicity complement each other in varying extents. Evaluation of the relative weights of these resonance forms requires proper bonding description with a well-balanced toolbox of analytical methods.

NHC adducts of tantalum amidohalides: the first example of NHC abnormally coordinated to an early transition metal.

The reaction of Ta(NMe) with NHC·HBF (NHC = IMes and SIMes) leads to new carbene adducts of the mixed Ta amidofluoride, [(NHC)TaF(NMe)]. On the contrary, the reaction of Ta(NMe) with IMes·HCl gives a complex mixture, where [(aIMes)TaCl(NMe)] is identified as one of the products. This is the first example of abnormal NHC coordination to an early transition metal.

Spin polarization transfer mechanisms of SABRE: A magnetic field dependent study.

We have investigated the magnetic field dependence of Signal Amplification By Reversible Exchange (SABRE) arising from binding of para-hydrogen (p-H2) and a substrate to a suitable transition metal complex. The magnetic field dependence of the amplification of the (1)H Nuclear Magnetic Resonance (NMR) signals of the released substrates and dihydrogen, and the transient transition metal dihydride species shows characteristic patterns, which is explained using the theory presented here. The generation of SABRE is most efficient at low magnetic fields due to coherent spin mixing at nuclear spin Level Anti-Crossings (LACs) in the SABRE complexes.

Synthesis and structure of a paramagnetic Mo3S4 incomplete cuboidal cluster with seven cluster skeletal electrons.

The electron precise incomplete cuboidal complex [Mo(3)S(4)(dppe)(3)Br(3)]Br (1a) with 6 cluster skeletal electrons (CSE) and its halogen-mixed analogue [Mo(3)S(4)(dppe)(3)(Br,Cl)(3)](Br,Cl) (1b) can be smoothly reduced to the paramagnetic [Mo(3)S(4)(dppe)(3)X(3)] clusters (2a, X = Br; 2b, X = Cl/Br) with 7 CSE by treatment with liquid Ga.

Tris(tetra-butyl-ammonium) hexa-kis-(tert-butane-thiol-ato-κS)hepta-μ(3)-chlorido-μ(3)-sulfido-hexa-molybdate dihydrate.

The octa-hedral cluster core of the anion in the structure of the title compound, (C(16)H(36)N)(3)[Mo(6)(C(4)H(9)S)(6)(μ(3)-Cl)(7)(μ(3)-S)]·2H(2)O, has -3 site symmetry. Two μ(3)-Cl atoms fully occupy positions in the cluster core, while the remaining six positions are statistically occupied by Cl and S atoms in a 1:5 ratio. The fully occupied Cl-atom positions are located on sites with 3 symmetry, and the N atom of tetra-butyl-ammonium cation is located on a site with 2 symmetry.

Synthesis, molecular and electronic structure of an incomplete cuboidal Re3S4 cluster with an unusual quadruplet ground state.

A Re(IV) cluster complex [Re(3)(μ(3)-S)(μ-S)(3)(dppe)(3)Br(3)](+) with nine cluster skeletal electrons (CSE) and a quadruplet ground state has been prepared by treatment of [Re(3)S(7)Br(6)]Br with 1,2-bis(diphenylphosphino)ethane (dppe) in MeCN.

Unexpected transformation of a diamagnetic Mo3(μ3-S)(μ-S)3 to a paramagnetic Mo3(μ3-S)2(μ-S)3 cluster core by reaction of [Mo3S4(dppe)3Br3]PF6 with (t)BuSNa.

The electron precise [Mo(3)(μ(3)-S)(μ-S)(3)(dppe)(3)Br(3)](+) incomplete cuboidal complex with six cluster skeletal electrons (CSE) can be converted to the paramagnetic bicapped [Mo(3)(μ(3)-S)(2)(μ-S)(3)(dppe)(3)](+) cluster with an unusual seven metal electron population by treatment with (t)BuSNa, which simultaneously serves as a reducing agent and a source of the additional capping sulfur atom.