Recognition of self-assembled water-nitrate cluster in a Co(III)-2,2′-bipyridine host: Synthesis, X-ray structure, DNA cleavage, molecular docking and anticancer activity

Abstract

A mononuclear cobalt(III) complex [Co(bpy) 2 Cl 2 ]NO 3 •2H 2 O (1) (bpy = 2,2-bipyridine) has been synthesized and crystallographically characterized. Self-assembly of the lattice water molecules from rectangular tetrameric water cluster interacts with nitrate anion along the c-axis forming a six membered hexagonal water-nitrate cluster. It presents a new mode of association of water molecules with nitrate molecules which is not predicted theoretically or found experimentally. The molecule effectively cleaves bacterial genomic DNA and shows important cytotoxicity against human hepatocarcinoma cell (HepG2).

Crystal Structure of <i>cis</i>-Bis(2,2′-bipyridyl)dichlorocobalt(III) Nitrate Methanol Solvate

“…The crystal data and selected bond lengths and angles are summarized in Tables 1 and 2 distances and the angles around the Co(III) ion were quite similar to those of cis-[CoCl2(bpy)2](X)•2H2O (X = Clor NO3 -). 6,7 Moreover, the lattice parameters were also similar to those of two other previous reported complexes 6,7 (Table S1). The Cl•••H-C contacts between a Cl(2) atom and two H atoms of the 3-and 3′-positions in the bpy(N(1),N(2)) ligand in an adjacent cation complex, and the π-π stacking contacts between a bpy(N(1),N(2)) ligand and another bpy(N(1),N(2)) ligand in an adjacent cation complex, were observed in the crystal to form 1-D cationic chains (Fig.…”

“…It brought about an efficient cleavage of double-stranded DNA without the requirement of an external agent in a concentration-dependent manner. 6 Similar 1-D water-anion chains were also observed in the Cl-salt, 7 though it is not described in this report. These crystal structures of cis- 6,7 indicated that a complex cation, cis-[CoCl2(bpy)2] + , would have two kinds of 1-D chains in the crystal without depending on a kind of counter ion.…”

“…3 These are not only used as starting materials for many functional complexes, 4,5 but also the cis-bis(N-N)cobalt(III) complexes have been investigated concerning their chemical and biological properties. 6 In 2016, the crystal structure and anticancer activity of cis-[CoCl2(bpy)2](NO3)•2H2O were reported by Das and co-workers. 6 The structure parameters of a cation part were similar to those of the previously reported crystal structure, [CoCl2(bpy)2]Cl•2H2O.…”

“…6 In 2016, the crystal structure and anticancer activity of cis-[CoCl2(bpy)2](NO3)•2H2O were reported by Das and co-workers. 6 The structure parameters of a cation part were similar to those of the previously reported crystal structure, [CoCl2(bpy)2]Cl•2H2O. 7 Das and co-workers focused on 1-D water-anion chains, which were ladder-shape hydrogen bonding networks between counter ions, NO3 -, and square units of four lattice water molecules connected by hydrogen bonding interactions, in the crystal, because polypyridyl moieties that were present in biological molecules might stabilize various water topologies in the environment, resembling those in living system.…”

“…Herein, we report on the crystal structure of cis-[CoCl2(bpy)2](NO3)•CH3OH (Fig. 1), and compare it with cis-[CoCl2(bpy)2](X)•2H2O (X = Clor NO3 -) 6,7 to find the feature of the cis-[CoCl2(bpy)2] + complex in the crystal. In the result, we found that the cationic part in this complex was also similar to those in two previously reported complexes, although this crystal had no 1-D water-anion chains.…”