John Bacsa

{N-alkyl-N-[pyridin-2-ylmethylene] amine}dichloro palladium(II) complexes: synthesis, crystal structures and evaluation of their catalytic activities for ethylene polymerization

Abstract Three pyridinylimine palladium(II) complexes of the type [(C5H4N)HCN(CH2)n-CH3] PdCl2 (n=4, 7, 11) were synthesized by reacting (COD)PdCl2 with the appropriate pyridyl-imine ligand. The crystal structure of the complex, where n=7 was determined using single crystal X-ray crystallography and this displays a striking co-planar geometry, with the pyridine ring, the metal coordination sphere N(1)C(5)C(6)N(2)Pd and the alkyl backbone all being in the same plane. The three complexes prepared were evaluated as catalyst precursors for ethylene polymerization. Activation with methylaluminoxane (MAO) leads to the formation of an active catalyst species, which produces only high-density polyethylene. The effect of the chain length of the alkyl substituent at the imino nitrogen on the catalytic activity was evaluated. It was found that the molecular weight of the polymer increases as the chain length increases, although a higher level of MAO was required to reach optimum activity.

Anion dependence of Ag(I) reactions with 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine (bptz): isolation of the molecular propeller compound [Ag2(bptz)3][AsF6]2

The new compound [Ag(2)(bptz)(3)][AsF(6)](2), prepared from the reaction of bptz with Ag[AsF(6)] in CH(3)CN, is stable in solution as well as the solid-state and exhibits an unprecedented propeller arrangement of three bptz ligands spanning two Ag(i) ions with [AsF(6)](-) anions located in the folds of the cation.

The synthesis and crystal structure of {N-dodecyl-N-pyridin-2-ylmethylene]amine}dichloro palladium and its preliminary evaluation as a catalyst for ethylene polymerization

Abstract The new pyridylimine complex, {N-dodecyl-N-[(1E)-pyridin-2-ylmethylene]amine}dichloro palladium was synthesized by the reaction of N-(dodecanyl)pyridyl-2-methanimine with (COD)PdCl2. The complex when activated with methylaluminoxane polymerizes ethylene to produce only high-density polyethylene under mild reaction conditions.

Synthesis, Characterization, and Physical Properties of Two Trinuclear, Mixed-Valence Species of Type [μ3-OMnIIMnIII2(O2CCF3)6(R)3] (R=H2O, CH3COOH)

The preparation and characterization of two new mixed-valence, trinuclear species, [Mn3O(O2CCF3)6(H2O)3]⋅CF3COOH⋅4/3H2O (1) and [Mn3O(O2CCF3)6(CH3COOH)3] (2), is reported. Compound 1 crystallizes in the triclinic space group, P¯1 (No. 2), with the parameters, a=12.3131(9) Å, b=12.4427(9) Å, c=12.965(1) Å, α=72.593(4)°, β=73.453(5)°, γ=68.345(4)°, V=1727.2(2) Å3, and Z=2. A total of 14060 reflections were collected in the range 1.68≤θ≤27.52°. The final weighted and non-weighted agreement indices, R1=0.0589 and wR2=0.1445 were based on a total of 6953 unique reflections with an Rint value of 0.0542. Compound 2 crystallizes in the monoclinic space group, P21/n (No. 14), with the parameters, a=12.876(3) Å, b=12.212(4) Å, c=17.732(4) Å, β=100.40(3)°, V=3640.4(1) Å3, and Z=4. A total of 32197 reflections were collected in the range 1.72≤θ≤27.13°. The final weighted and non-weighted agreement factors, R1=0.0647 and wR2=0.1609 were based on a total of 8018 unique reflections with an Rint value of 0.0462. An investigation of the physical properties revealed that both compounds display an intermediate ground state of S=3/2 as a consequence of intramolecular antiferromagnetic coupling. The magnetic data for compound 1 was best fit to the parameters g=2.09, J=−5.5 cm−1, J′=−3.4 cm−1, and DMn(III)=−4.5 cm−1; the data for compound 2 was best fit to the parameters g=2.10, J=−2.9 cm−1, J′=−5.5 cm−1, and DMn(III)=−4.5 cm−1.

A high spin molecular square based on square pyramidal CoII and tetrahedral MnII centers: [{MnIICl2}2{CoII(triphos)(CN)2}2]

A high spin molecular square of square pyramidal Co(II) and tetrahedral Mn(II) corners exhibiting an overall S= 4 ground state has been crystallized and its magnetic properties investigated.

1,3‐Di­thiol­an‐2‐one

The title compound, C3H4OS2, possesses pseudo-twofold symmetry and consists of a twisted five-membered ring of three C and two S atoms, with a ketone O atom in an equatorial position.