Crystal structure and Hirshfeld surface analysis of 6,6'-dimethyl-2,2'-bi-pyridine-1,1'-diium tetra-chlorido-cobaltate(II).

In the title mol-ecular salt, (C12H14N2)[CoCl4], the dihedral angle between the pyridine rings of the cation is 52.46 (9)° and the N-C-C-N torsion angle is -128.78 (14)°, indicating that the ring nitro-gen atoms are in anti-clinal conformation. The Cl-Co-Cl bond angles in the anion span the range 105.46 (3)-117.91 (2)°. In the extended structure, the cations and anions are linked by cation-to-anion N-H⋯Cl and C-H⋯Cl inter-actions, facilitating the formation of R 4 4(18) and R 4 4(20) ring motifs. Furthermore, the crystal structure features weak anion-to-cation Cl⋯π inter-actions [Cl⋯π = 3.4891 (12) and 3.5465 (12) Å]. Hirshfeld two-dimensional fingerprint plots revealed that the most significant inter-actions are Cl⋯H/H⋯Cl (45.5%), H⋯H (29.0%), Cl⋯C/C⋯Cl (7.8%), Cl⋯N/N⋯Cl (3.5%), Cl⋯Cl (1.4) and Co⋯H (1%) contacts.

9-(4-Meth-oxy-phen-yl)-9H-carbazole.

In the title compound, C19H15NO, the dihedral angle between the benzene rings of the carbazole moiety is 1.73 (12)° and the meth-oxy-substituted phenyl ring deviates from the mean plane of the carbazole grouping (r.m.s. deviation = 0.020 Å) by 56.78 (8)°. In the crystal, weak C-H⋯π inter-actions link the mol-ecules. The two-dimensional fingerprint plots derived from the Hirshfeld surface indicate that H⋯H (51.2%) and C⋯H/H⋯C (39.9%) contacts dominate the packing.

2-[(5-Chloro-pyridin-2-yl-imino)-meth-yl]phenol.

In the title compound, C12H9ClN2O, the dihedral angle between the aromatic rings is 1.78 (4)° and an intra-molecular O-H⋯N hydrogen bond closes an S(6) ring. In the crystal, C-H⋯O and C-H⋯N hydrogen bonds connect the mol-ecules into [001] chains.

(3S,5R,6S)-Di-phenyl-methyl 1-oxo-6-bromo-penicillanate.

In the title compound, C21H20BrNO4S, a key inter-mediate in the synthesis of the widely used ß-lactamase inhibitor tazobactam, the five-membered thia-zolidine ring adopts an envelope conformation and the four-membered azetidine ring is in a distorted planar conformation. The crystal structure features C-H⋯O hydrogen bonds and a weak C-H⋯π inter-action.