Crystal structure of tris-(1,3-dimesityl-4,5-di-hydro-1H-imidazol-3-ium) tetra-bromido-cobaltate(II) bromide chloro-form hexa-solvate.

In the unit cell of the title compound, (C21H27N2)3[CoBr4]Br·6CHCl3, the tetrabromidocobaltate(II) anion and the bromide anion are located on a crystallographic threefold rotation axis. For the [CoBr4](2-) group, the axis runs through one of the Br ligands and the Co(II) atom. All other structure moieties lie on general sites. Various tris-(1,3-dimesityl-4,5-di-hydro-1H-imidazol-3-ium) structures with different counter-ions have been reported. In the title compound, the N-C-N angle is 113.7 (5)°, with short C-N bond lengths of 1.297 (7) and 1.307 (7) Å. The two mesityl planes make a dihedral angle of 34.6 (1)° and the dihedral angles between the mesityl and N-C-N planes are 82.0 (1) and 88.5 (1)°, respectively. The imidazoline ring is almost planar, with atom deviations in the range 0.003 (5)-0.017 (5) Šfrom the best plane; the mean deviation is 0.012 (5) Å. In the crystal, non-covalent inter-actions of the C-H⋯Br type occur between the Br(-) anion and the cation, as well as between the [CoBr4](2-) anion and both the chloro-form solvent mol-ecules. These H⋯A distances are slightly shorter than the sum of van der Waals radii.

Crystal structures of di-iodido-bis-[(1S,5S)-4-mesityl-1,2,8,8-tetra-methyl-2,4-di-aza-bicyclo-[3.2.1]octan-3-yl-idene-κC (3)]palladium(IV) and di-chlorido-[(1S,5S)-4-mesityl-1,2,8,8-tetra-methyl-2,4-di-aza-bicyclo[3.2.1]octan-3-yl-idene-κC (3)](tri-phenyl-phosphane-κP)palladium(IV).

The mol-ecular structures of the chiral title compounds, [Pd(C19H28N2)2I2], (I), and [Pd(C19H28N2)Cl2(C18H15P)], (II), show a distorted square-planar coordination around the Pd(II) atoms with two halogenide (Hal) ligands each and two N-heterocyclic carbene (NHC) ligands in (I) or one NHC and one tri-phenyl-phosphane ligand in (II). The deviations of the Pd(II) atoms from the L 2Hal2 best plane (L = NHC or tri-phenyl-phosphane ligand) are 0.206 (1) Šfor (I) and 0.052 (1) Šfor (II). The crystal packings exhibit inter-molecular C-H⋯Hal hydrogen bonds.

Crystal structure of di-bromido-bis-(1,3-dibenzyl-1,3-diazinan-2-one-κO)cobalt(II).

The unit cell of the title complex, [CoBr2(C18H20N2O)2], contains 1.5 formula units per asymmetric unit with one mol-ecule sitting on a general site and a second one halved by a crystallographic twofold rotation axis passing through the Co(II) cation. Both Co(II) atoms are coordinated in a distorted tetra-hedral manner by two Br(-) ligands and two O atoms of the pyrimidinone (OPyr) groups. The Br-Co-Br coordination angles are similar [115.46 (4) and 115.20 (5)°], while the O-Co-O angles differ slightly more [102.26 (18) and 98.1 (2)°]. Similarly, the Co-Br bond lengths are almost identical [2.3721 (9), 2.3757 (10) and 2.3809 (10) Å], with a larger difference between the Co-O bond lengths [1.929 (4), 1.926 (4) and 1.955 (4) Å]. The three independent OPyr groups present envelope conformations, with three C and two N atoms lying in well defined planes with maximum deviations from the least-squares planes of 0.047, 0.031 and 0.036 Å, and the external-most C atoms protruding by 0.654 (6), 0.643 (7) and 0.656 (6) Šout of the planes. The dihedral angles between the planar fractions of the OPyr planes are 50.5 (1)° for the nonsymmetric mol-ecule and 49.7 (1)° for the symmetric one. Non-covalent inter-actions are of the C-H⋯Br type and they are weak, hardly shorter than van der Waals radii, with an H⋯Br distance range of 3.00-3.04 Å. The inter-molecular inter-actions define chains parallel to [101].