Syntheses, structures, and properties of two mononuclear cobalt(III) azido complexes containing a tetradentate N-donor Schiff base as end-capping ligand

Abstract

Two hexacoordinated mononuclear Co(III) compounds of the type cis-[Co(L)(N 3 ) 2 ] X [1, X = ClO 4 ; 2, X = PF 6 ; L = N,N 0 -(bis(pyridine-2-yl)benzylidine)-1,4-butanediamine] have been synthesized and characterized by physicochemical and spectroscopic methods. The crystal structures of complexes 1 and 2 both have distorted octahedral geometry with two terminal azides in mutual cis orientations. In the crystalline state, two mononuclear units of 1 are associated by weak C-H…p interactions to produce a dimeric unit, which packs through C-H…O hydrogen bonds and p…p interactions leading to a 2-D continuum. The mononuclear units in 2 are engaged in weak cooperative intermolecular C-H…p interactions and multiple C-H…F hydrogen bonds giving rise to a 3-D network structure. These diamagnetic compounds are redox active and show luminescence in DMF solutions.

Synthesis, Characterization and Crystal Structure of Cobalt(II) Complex of a Schiff Base Derived from Isoniazid and Pyridine-4-Carboxaldehyde

“…The bite angles O(5)-Co(1)-O(6); 90.39˚(7),O(5)#1-Co(1)-O(6); 89.61˚(7), O(5)-Co(1)-O(6)#1; 89.61˚(7); O(5)#1-Co(1)-O(6)#1; 90.39˚(7), O(5)-Co(1)-N(4); 89.73˚(7), O(5)#1-Co(1)-N(4); 90.27˚(7), O(6)-Co(1)-N(4); 92.47˚(7), O(6)#1-Co(1)-N(4); 87.53˚(7), O(5)-Co(1)-N(4)#1; 90.27˚(7), O(5)#1-Co(1)-N(4)#1; 89.73˚(7), O(6)-Co(1)-N(4)#1; 87.53˚(7), O(6)#1-Co(1)-N(4)#1; 92.47˚(7) are all very close to 90˚, revealing the least distortion of the octahedral geometry. This geometry observed in this complex is similar to that of other compounds reported elsewhere[12]. The distortion around the metal centre is negligible hence the complex is symmetric about the metal centre.…”

“…The coordination chemistry of cobalt is of considerable interest since Cobalt(II) and Cobalt(III) complexes derived from Schiff bases are reported to be biologically active [11]. The cobalt Schiff base complexes are also an important class of coordination compounds, not only because of their involvement in Vitamin B12 models and oxygen carrier properties, but also due to their interesting magnetic and spectroscopic as well as diverse metal-ligand interactions [5] [12].…”

Synthesis and Crystal Structure of N-(2-Pyridylmethyl)-L-Alanine) Isothiocyanate Cobalt(III)

“…The X-ray crystal structure reveals that the thiocyanate anion in the crystal lattice is not bonded to the Co(III) centre but forms interionic hydrogen bonds [17] [19]]. The bond angle of the N-C-S thiocyanate anion is within the expected range of 178˚ -182˚ [18].…”

Synthesis, Characterisation and Antimicrobial Study of Cobalt (II) Complex of A Schiff Base Derived from Isonicotinic Acid Hydrazide and 4-Chlorobenzaldehyde

“…Thus, in the present work INH based SB is synthesized and complexed with cobalt. The coordination chemistry of cobalt has a considerable interest since cobalt complexes derived from SB are reported to be biologically active 15 . The cobalt SB complexes are also an important class of coordination compounds, not only because of their involvement in Vitamin B12 models and oxygen carrier properties, but also due to their interesting magnetic and spectroscopic as well as diverse binding ability 16 .…”