Daron E. Janzen

1-Phenyl­piperazine-1,4-diium tetra­chlorido­cobalt(II)

In the title molecular salt, (C10H16N2)[CoCl4], the piperazine ring of the phenylpiperazine dication adopts a chair conformation and the phenyl ring occupies an equatorial orientation. In the tetrachloridocobaltate(II) dianion, the Co—Cl bond lengths for the chloride ions not accepting hydrogen bonds are significantly shorter than those for the chloride ions accepting such bonds. In the crystal, the components are linked by N—H⋯Cl hydrogen bonds, generating [001] chains.

trans-Acetyl­dicarbon­yl(η5-cyclo­penta­dien­yl)(methyl­diphenyl­phosphane)molybdenum(II)

The title compound, [Mo(C5H5)(C2H3O)(C13H13P)(CO)2], was prepared by reaction of [Mo(CH3)(C5H5)(CO)3] with methyldiphenylphosphane. The MoII atom exhibits a four-legged piano-stool coordination geometry with the acetyl and phosphane ligands trans to each other. There are several intermolecular C—H⋯O hydrogen-bonding interactions involving carbonyl and acetyl O atoms as acceptors. A close nearly parallel π–π interaction between the cyclopentadienyl plane and the phenyl ring of the phosphane ligand is present, with an angle of 6.4 (1)° between the two least-squares planes. The centroid-to-centroid distance between these groups is 3.772 (3) Å, and the closest distance between two atoms of these groups is 3.449 (4) Å. Since each Mo complex is engaged in two of these interactions, the complexes form an infinite π-stack coincident with the a axis.

Crystal structure of 2,5-di-methyl-anilinium hydrogen maleate.

The crystal structure of the title salt, C8H12N+·C4H3O4 −, consists of a 2,5-dimethylanilinium cation and an hydrogen maleate anion. In the anion, a strong intramolecular O—H⋯O hydrogen bond is observed, leading to an S(7) graph-set motif. In the crystal, the cations and anions pack in alternating layers parallel to (001). The ammonium group undergoes intermolecular N—H⋯O hydrogen-bonding interactions with the O atoms of three different hydrogen maleate anions. This results in the formation of ribbons extending parallel to [010] with hydrogen-bonding motifs of the types R 4 4(12) and R 4 4(18).

trans-Acetyl­dicarbon­yl(η5-cyclo­penta­dien­yl)[tris­(furan-2-yl)phosphane-κP]molybdenum(II)

The title compound, [Mo(C5H5)(C2H3O)(C12H9O3P)(CO)2], was prepared by reaction of [Mo(C5H5)(CO)3(CH3)] with tris(furan-2-yl)phosphane. The MoII atom exhibits a four-legged piano-stool coordination geometry with the acetyl and phosphine ligands trans to each other. The O atom of the acetyl ligand points down, away from the Cp ring. In the crystal, molecules form centrosymmetrical dimers via π–π interactions between furyl rings [the centroid–centroid distance is 3.396 (4) Å]. The dimers are linked by C—H⋯O hydrogen bonds into layers parallel to (100).

Tri­chlorido­(1-ethyl­piperazin-1-ium)cobalt(II)

In the title complex, [Co(C6H15N2)Cl3], the Co2+ ion is coordinated in a distorted tetrahedral fashion by three chloride ions and one N atom of the piperazine ring; the ring adopts a chair conformation with the N—Co and N—CEt bonds in equatorial orientations. In the crystal, molecules are connected by N—H⋯Cl hydrogen bonds, generating (10-1) sheets.

Pyridinium-Functionalized Pyromellitic Diimides with Stabilized Radical Anion States

In this work, we report the stabilization of the reduced states of pyromellitic diimide by charge-balancing the imide radical anions with cationic pyridinium groups attached to the aromatic core. This structural modification is confirmed by single-crystal X-ray diffraction analysis. Characterization by (spectro)electrochemical experiments and computations reveal that the addition of cationic groups to an already electron-deficient ring system results in up to +0.57 V shifts in reduction potentials, largely as a consequence of charge screening and lowest unoccupied molecular orbital-lowering effects. This formal charge-balancing approach to stabilizing the reduced states of electron-deficient pyromellitic diimides will facilitate their incorporation into spin-based optoelectronic materials and devices.

Crystal structures of five 1-alkyl-4-aryl-1,2,4-triazol-1-ium halide salts.

To investigate the predominant intermolecular interactions in 1-alkyl-4-aryl-1,2,4-triazol-1-ium halide salts, five salts were prepared and crystallographically characterized. The halide ions generally interact with the H atoms of the triazolium cation forming extended sheets. When the aryl ring lies on the plane of the triazolium cation, the cationic core formed two-dimensional networks that lead into layer-like assembled structures. The triazolium core exhibits π–π interactions with the iodide and/or the aryl ring of another layer. The melting-point temperatures of each salt were also determined.

Crystal structures of 2,6-bis-[(1H-1,2,4-triazol-1-yl)meth-yl]pyridine and 1,1-[pyridine-2,6-diylbis(methyl-ene)]bis-(4-methyl-1H-1,2,4-triazol-4-ium) iodide triiodide.

The predominant intermolecular interactions for triazole rings involve the acidic hydrogen in the third position as shown by the title compound, 2,6-bis[(1H-1,2,4-triazol-1-yl)methyl]pyridine, (I), and the salt 1,1′-[pyridine-2,6-diylbis(methylene))bis(4-methyl-1H-1,2,4-triazol-4 -ium] iodide triiodide, (II).

Molecular structure, spectroscopic, dielectric and thermal study, nonlinear optical properties, natural bond orbital, HOMO-LUMO and molecular docking analysis of (C 6 Cl 2 O 4 ) (C 10 H 14 N 2 F) 2 ·2H 2 O

A new chloranilate compound with 1-(2-fluorophenyl)piperazine has been synthesized and characterized using spectroscopic methods and X-ray diffraction. The atomic arrangement can be described by an H-bonded 3D network, formed by anionic entities, organic cations and H2O molecules linked together via NH…O, OH…Cl, CH…Cl and CH…O hydrogen bonds. The vibrational absorption bands of the various characteristic groups of this compound have been identified by infrared spectroscopy. Moreover, the thermal and dielectric analyses have shown that the title compound has a phase transition at 393 K. The surface mapped over the dnorm property, highlights the A⋯H (AO, C, Cl and F) as the main intermolecular contacts. On the other hand, the geometry, intermolecular bonds and harmonic vibrational frequencies of the title molecule have been investigated using the B3LYP/6-31G (d, p) method. The stability of the structure obtained, as well as the charge transfer within the molecule, have been confirmed by determining the energies of the HOMO and LUMO levels and the theoretical gap energy. Molecular docking studies of the title compound have also been conducted as part of this study.

Benzodithiophene homopolymers via direct (hetero)arylation polymerization

Direct (hetero)arylation polymerization (DHAP) of a monobrominated benzo[1,2-b:4,5-b′]dithiophene monomer using the Herrmann–Beller catalyst with a tertiary phosphine provided benzodithiophene homopolymers in good yields. Employing both P(o-OMePh)3 and P(o-NMe2Ph)3 as the phosphine ligands gave well-defined polymers—with the later phosphine providing a higher molecular weight polymer. The preparation of a benzodithiophene (BDT) trimer was used to assist in the assignment of the 1H NMR spectra of the synthesized polymers which show largely defect-free couplings. The optical spectra of polymers formed via DHAP and those prepared using traditional Stille couplings are essentially identical, which further confirms the presence of well-defined BDT–BDT couplings along the conjugated polymer chain. These results confirm that carboxylic acid additives are not always necessary to suppress defects in DHAP polymerizations and that DHAP is a viable alternative to traditional Stille coupling for the preparation of benzodithiophene homopolymers.