Natural cyclic tetrapyrroles feature outstanding capacity for binding transition metal ions, furnishing Nature with the important metallo-porphyrinoid 'Pigments of Life', such as heme, chlorophyll (Chl) and vitamin B12. In contrast, linear tetrapyrroles are not generally ascribed a biologically relevant ability for metal-binding. Indeed, when heme or Chl are degraded to natural linear tetrapyrr...

Thiosemicarbazones are Schiff based ligands which have gained importance over the decades as potential drug candidates. When coordinated to metals, they have proved as good anticancer, antimicrobial, antioxidant and antiprotozoal agents. Numerous applications of these ligands in the field of Analytical Chemistry have also been reported. The present review aims to summarize some of the recent ad...

Among the many interesting chemical and physical properties of transition-metal ions is their curious ability to exhibit two different magnetic moments when combined with various ligand groups. The existing hybrid orbital treatment of these transition-metal complexes correlates the experimentally measured magnetic moments with the bond character between metal and ligand; that is, these complexe...

A series of transition metal complexes of Cu(II), Ru(II), Fe(II), Mo(II) with a tetradentate ligand, bis (2-hydroxy benzylidene) benzidine prepared by the condensation of 2-hydroxy benzaldehyde and benzidine. Metal complexes are reported and characterized based on elemental analysis IR, HNMR, Magnetic moment, molar conductance and thermal analysis. The synthesized ligands in comparison to their...

Two mononuclear U02(VI) complexes of the general formula [(HL)U02(OH2)2] О.бШО, where L is a pentadentate N2O3 asymmetric Schiff base ligand, were synthesized and used as ligands for further coordination of either Cu(II) or Ni(II) ions. The U02(VI) ion occupies the outer O2O sites of the ligands, thus leaving the inner N2O2 sites of the ligands vacant for further coordina­ tion. Different types...

We have investigated the molecular geometries of a series of dicoordinated d(10)-transition-metal complexes ML2 (M=Co(-), Rh(-), Ir(-), Ni, Pd, Pt, Cu(+), Ag(+), Au(+); L=NH3, PH3, CO) using relativistic density functional theory (DFT) at ZORA-BLYP/TZ2P. Not all complexes have the expected linear ligand-metal-ligand (L-M-L) angle: this angle varies from 180° to 128.6° as a function of the metal...

Over the last 2 decades, the rapid development of new synthetic routes for the preparation of expanded porphyrin macrocycles has allowed for the exploration of a new frontier consisting of "porphyrin-like" coordination chemistry. In this Account, we summarize our exploratory forays into the still relatively poorly explored area of oligopyrrolic macrocycle metalation chemistry. Specifically, we ...

Murexide, a reddish purple compound has the structure shown in Fig. 1. It has received much interest because of its application in chemical analysis and spectrophotometric fields [1, 2]. It is considered as the ammonium salt of purpuric acid and named as ammonium 2,6-dioxo-5-(2,4,6-trioxo-tetrahydro-pyrimidine-5-ylidene amino)-1,2,3,6-tetrahydro-pyrimidine-4-olate. It serves as a metal ion indi...