A DFT STUDY ON THE HYDROLYSIS MECHANISM OF THE NAMI-A-TYPE ANTITUMOR COMPLEX (HL)[trans-RUCl₄L(dmso-S)](L=4-amino-1,2,4-triazole)

Abstract

The hydrolysis process of Ru (III) complex (HL)[trans- RuCl 4L(dmso-S)] (L=4-amino-1,2,4-triazole) (1), a potential antitumor complex similar to the well-known antitumor agent (ImH)[trans- RuCl 4(dmso-S)(Im)](NAMI-A), was investigated using density functional theory (DFT) with the conductor-like polarizable continuum model (CPCM). The structural characteristics and the detailed energy profiles for the hydrolysis processes of this complex were obtained. For the first hydrolysis step, complex 1 with 4-amino-1,2,4-triazole ligand shows much faster aquation than NAMI-A with imidazole ligand and complex 2 with 4H-1,2,4-triazole ligand, and such a calculated result is in good agreement with the experimental one. For the second hydrolysis step, the formation of cis-diaqua products is found to be thermodynamically preferred over the trans isomers. In addition, on the basis of the analysis of electronic characteristics of species in the hydrolysis process, the trend in abilities (A) of hydrolysis products attacked nucleophilicly by pertinent biomolecules is revealed. These theoretical results will help in understanding the action mechanism of this potential Ru (III) drug with pertinent biomolecular targets.

Theoretical studies on a series of 1,2,4-triazoles derivatives as potential high energy density compounds

“…Numbers in bold mean that the corresponding bond is most reactive in the studied compounds the BDE of the N 2 -N 3 bond is 50.4 kcal/mol, which is larger than that of the C 5 -N 5 bond and smaller than that of the C 1 -N 1 bond. For compound (5), the BDEs of the C 1 -N 1 and C 5 -N 5 bonds are equivalent and are all equal to 60.9 kcal/mol, while the BDE of the C 2 -N 2 bond is 87.4 kcal/mol. The BDEs of the C 1 -N 1 and C 5 -N 5 bonds are also equivalent for compound (6) and is equal to 61.3 kcal/mol, which is larger than that of the C 3 -N 3 bond.…”

“…Bond dissociation energies (BDE, kcal/mol) of some isomeric structures of the compound 5 at B3LYP/6-31G** level. The bold-faced number means that the corresponding bond is most reactive in the studied compound (5), which are the weakest bonds. A possible explanation for the above behaviour is that the presence of the weak interaction between O atom of nitro group and adjacent hydrogen atom, weakens the C-NO 2 bond length.…”

“…Triazoles and their derivatives have also been widely used in the field of agriculture, biology, medicine and photoelectricity duplication. [3][4][5] The nitro group is an important group for energetic materials. 6 Through increasing numbers of the nitro group, the compounds' density and the number of mole gaseous combustion products formed by per gram of material can be increased, thereby enhancing * For correspondence propellant performance.…”

Importance of Hydrogen Bonding: Structure–Activity Relationships of Ruthenium(III) Complexes with Pyridine-Based Ligands for Alzheimer’s Disease Therapy

“…Similar behavior has been previously reported for NAMI-A, 85 where the hydrolysis mechanism is a stepwise process, as both a chloride and DMSO are lost. 86 While computational studies have suggested chloride ligand exchange to be prominent, 87,88 experimental studies have demonstrated that the DMSO is lost preferentially. 60,82 Previous EPR studies of Ru-P1 and Ru-P2 provide additional supportive evidence that the DMSO ligand is predominantly lost during the first step, while subsequent aquation leads to several soluble poly-aquated derivatives.…”

Solvent Effect on the Structural, Electronic, Spectra Properties and First Hyperpolarizability of W(co)5l, L=(4-Pyridylmethylene)malononitrile

“…It is well-known that the solvent polarity influences both the structure and properties of conjugated organic molecules and metal complexes [53][54][55]. The structural data for the optimized structures of W(CO) 5 -pyridine-π-acceptor complex in six studied solvents are gathered in Table 2.…”