Observation of a Distribution of Internal Transverse Magnetic Fields in a Mn12-Based Single Molecule Magnet

A distribution of internal transverse magnetic fields has been observed in single molecule magnet (SMM) Mn12-BrAc in the pure magnetic quantum tunneling (MQT) regime. Magnetic relaxation experiments at 0.4 K are used to produce a hole in the distribution of transverse fields whose angle and depth depend on the orientation and amplitude of an applied transverse ``digging field.'' The presence of such transverse magnetic fields can explain the main features of resonant MQT in this material, including the tunneling rates, the form of the relaxation and the absence of tunneling selection rules. We propose a model in which the transverse fields originate from a distribution of tilts of the molecular magnetic easy axes.Comment: 4 page

Regarding the structures and fluxionality of tricyclopentadienylaluminum compounds

Contains fulltext : 29357___.PDF (publisher's version ) (Open Access

Formation of a novel delocalised diphosphazene upon complexation. The preparation and X-ray structure of Pd2Cl4[(CF 3)2P=N=PPh3]2

10.1039/C39900001580Journal of the Chemical Society, Chemical Communications221580-158

Hydrothermal synthesis and characterization of {[Ni2(NA)4(µ-H2O)]·2H2O}n (HNA = nicotinic acid) and its heterogeneous catalytic effect

A carboxylate-bridged metal-organic coordination polymer {[Ni2(NA)4(µ-H2O)]·2H2O}n (1, HNA = nicotinic acid) has been synthesized under hydrothermal conditions and characterized by FT-IR, TG/DTA, micro analysis and single-crystal X-ray diffraction. 1 has an interesting 3D network structure and adjacent networks are further connected together via strong ?-? packing interactions. The thermal behavior and catalytic performance of 1 were investigated and its selectivity was measured as 100% for the oxidation of thymol (T) to thymoquinone (TQ). © 2015 Elsevier Ltd. All rights reserved.The authors gratefully acknowledge financial support from the Research Unit of Çukurova University (Grant No. FEF2013D5 ). Appendix

Hydrothermal synthesis, crystal structure and heterogeneous catalytic activity of a novel inorganic-organic hybrid complex, possessing infinite La-O-La linkages

In this paper, a novel lanthanum coordination polymer formulated as {[La2(Hpdc)3(H2O)4]·2H 2O}n (1, H3pdc = 3,5-pyrazoledicarboxylic acid) has been synthesized by the reaction of H3pdc with chloride salt of La(III) under hydrothermal conditions and characterized by elemental analysis, FT-IR, TGA and single-crystal X-ray diffraction. The complex crystallized in the monoclinic system Cc space group. The single-crystal X-ray structural analysis revealed that central metal La atoms are nine-coordinate and linked by bridging µ2-OCOO - groups to form [La(1)- (µ2-OCOO -)2-La(2)]n inorganic-organic chains that produce a supramolecular polymeric framework structure. The three-dimensional structure of 1 is accompanied by non-coordinating water molecules. Thermal behavior and catalytic performance of 1 have also been studied. The complex 1 showed 100% selectivity and a conversion rate of 24% on the oxidation of thymol (T) to thymoquinone (TQ). © 2013 Elsevier B.V. All rights reserved.The authors gratefully acknowledge financial support from the Research Unit of Cukurova University (Grant No. FEF 2010 BAP15 ). Appendix

Synthesis and crystal structures of (CF3)2As-N=PPh3, [Os3(CO)11{(CF3)2As=N=PPh 3}] and [Os3(μ-H)2(CO)9{(CF3) 2As=N=PPh3}]

10.1039/DT9930000663Journal of the Chemical Society, Dalton Transactions5663-66

Designing bifunctional alkene isomerization catalysts using predictive modelling

Controlling the isomerization of alkenes is important for the manufacturing of fuel additives, fine-chemicals and pharmaceuticals. But even if isomerization seems to be a simple unimolecular process, the factors that govern catalyst performance are far from clear. Here we present a set of models that describe selectivity and activity, enabling the rational design and synthesis of alkene isomerization catalysts. The models are based on simple molecular descriptors, with a low computational cost, and are tested and validated on a set of eleven known Ru-imidazol-phosphine complexes and two new ones. Despite their simplicity, these models show good predictive power, with R2 values of 0.60–0.85. Using a combination of principal components analysis (PCA) and partial least squares (PLS) regression, we construct a “catalyst map”, that captures trends in reactivity and selectivity as a function of electrostatic charge on the N* atom, EHOMO, polar surface area and the optimal mass substituents on P/distance Ru–P ratio. In addition to indicating “good regions” in the catalyst space, these models also give insight into mechanistic steps. For example, we find that the electrostatic charge on N*, EHOMO and polar surface area are crucial in the rate-limiting step, whereas the optimal mass of substituents on P/distance Ru–P is correlated with the product selectivity

Reactions of tetrakis(trifluoromethyl) diphosphine and bis(trifluoromethyl) phosphine with ruthenium carbonyl clusters; X-ray structure of tetraruthenium carbonyl cluster derivatives

Journal of Organometallic Chemistry5101-213-24JORC