One-pot hydrothermal synthesis of a mononuclear cobalt(II) complex and an organic-inorganic supramolecular adduct: Structures, properties and hirshfeld surface analyses.

Through the hydrothermal reaction of cobalt(II) perchlorate hexahydrate with 5-bromo-6-methyl-pyridine-2-carboxylic acid (5-Br-6-Me-Hpyc) and 1,4-bis(4-pyridyl)benzene (1,4-bpb) coligands, a cobalt(II) complex [Co(5-Br-6-Me-pyc) 2 (H 2 O)]·2H 2 O (1) and an organic-inorganic adduct [H 2 (1,4-bpb)]·2ClO 4 (2) have been co-synthesized in the same medium. Structural analyses indicated that the cobalt(II) ion in 1 is penta-coordinated by one water and two bidentate chelate 5-Br-6-Me-pyc anionic ligands to obtain an asymmetric mononuclear species. While in 2 , the two pyridyl groups of 1,4-bpb acquire two protons forming a bivalent cation pyridinium, which combine two perchlorate anions via N–H⋯O hydrogen bonds to fabricate an interesting anion-cation supramolecular adduct 2. The magnetism for 1 , fluorescence for 2 as well as the hirshfeld surface structures for them have been carefully described and discussed. A mononuclear cobalt(II) complex 1 and an anion-cation adduct 2 have been co-synthesized. There exists weak antiferromagnetic coupling in 1. 2 can emit strong purple emissions. The Hirshfeld surface analyses of 1 and 2 are consistent with the results of their crystal packing. [Display omitted] • One cobalt(II) compound 1 and an anion-cation adduct 2 have been co-synthesized. • There exists weak antiferromagnetic coupling in 1. • 2 can emit strong purple emissions. • The Hirshfeld surface analyses of their inter -molecular interactions conforms to the results of the crystal packing. • 1 and 2 are a new cocrystallization example and may be useful for other co-synthesis process. [ABSTRACT FROM AUTHOR]