Volume 38, Issue 4

In this review, the structural parameters of 18 heterotrinuclear Pt 2 M (M=Hg, Zn, Cd, Au, Mn, Ag, Pd), PtM 2 (M=Al, Ga, Sb, In, Mo, Fe), PtFeMn, PtHgMn, and PtFeOs types are summarized and analyzed. The Pt atoms are four-, five-, and even six-coordinated, among which the four-coordinated ones are the most common. The M atoms are found to be two- (Hg), three- (Hg), four- (Hg, Sb, In, Ag, Au), and six- (Ga, In, Al, Mo, Mn, Fe, Pd) coordinated and even sandwiched (FeC 10 ). There is a wide variety of donor atoms (ligands) (O+NL, N+CL, NL, CO, CN, CL, Cl, SL, PL, I), which build up the respective inner coordination spheres about the metal atoms. The 17 complexes contain two crystallographically independent molecules within the same crystal, and 1 complex contains four such molecules. In each complex, the respective molecules are differing mostly by the degree of distortion in metal-metal and metal-ligand bond distances and ligand-metal-ligand bond angles, and are examples of distortion isomerism.

Molecular structures of various d -element M(II) ion chelates with compartmental ( N , N )-, ( N , O )-, and ( N , S )-donor atomic ligands forming as a result of complexing with M(II) three or four articulated metal chelate cycles have been systematized and discussed in detail. It has been shown that, on the whole, such metalmacrocyclic compounds, as a rule, have molecular structures with non-coplanar chelate nodes and non-coplanar macrocycles. The review covers the period 2000–2017.

Nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H 2 S) are gaseous molecules of major impact in biology. Despite their toxicity, these molecules have profound effects on mammalian physiology and major implications in therapeutics. At tiny concentrations in human biology, they play key signaling and regulatory functions and hence are now labeled as “gasotransmitters.” In this literature survey, an introduction to gasotransmitters in relevance with NO, CO and H 2 S has been primarily focused. A special attention has been given to the conjoint physiological, pathophysiological and therapeutic aspects of NO in this work. In addition to the aforementioned elements of the investigation being reported, this report gives a detailed account of some of the recent advancements covering the NO release from both the nitro as well as nitroso compounds. The importance of the metallic center on the eve of producing the reduction center on NO and to develop photolabile properties have been elaborated within the effect of a few examples of metallic centers. Also, theoretical investigations that have been reported in the recent past and some other current theories pertaining to NO chemistry have been enlightened in this review. From the overall study, it is eminent that a number of facts are yet to be explored in context with NO for deeper mechanistic insights, model design for these molecules, other key roles and the search to find the best fit formalism in theoretical chemistry.