New diorganotin(IV) complexes of salicylaldehyde based hydrazones bearing furan heterocycle moiety: X-ray structural investigation of dimethyltin(IV) and diphenyltin(IV) complexes

A salicylaldehyde benzoyl hydrazone based near-infrared probe for copper(ii) and its bioimaging applications

Developing highly sensitive and selective methods for Cu²⁺ detection in living systems is of great significance in clinical copper-related disease diagnosis. In this work, a near infrared (NIR) fluorescent probe, CySBH, with a salicylaldehyde benzoyl hydrazone group as a selective and sensitive receptor for Cu²⁺ was designed and synthesized. The specific coordination of the salicylaldehyde benzoyl hydrazone group in CySBH with Cu²⁺ can induce a distinct quench of the fluorescence intensity, allowing for real-time tracking of Cu²⁺. We have demonstrated that CySBH could rapidly recognize Cu²⁺ with good selectivity and high sensitivity. Moreover, on the basis of low cell cytotoxicity, the probe was used to visualize Cu²⁺ in two cell lines by fluorescence imaging. Furthermore, CySBH can also be used to monitor Cu²⁺in vivo due to its NIR emission properties. These overall results illustrate that the NIR fluorescent probe CySBH provides a novel approach for the selective and sensitive monitoring of Cu²⁺ in living systems.

A near infrared fluorescent probe utilizing the salicylaldehyde benzoyl hydrazone group as the Cu²⁺ receptor was developed and used to selectively and sensitively monitor Cu²⁺ in living systems.

Synthesis, structure and bioactivity of Ni2+ and Cu2+ acylhydrazone complexes

Two acylhydrazone complexes, bis{6-methyl-N'-[1-(pyrazin-2-yl-κN¹)ethylidene]nicotinohydrazidato-κ²N',O}nickel(II), [Ni(C₁₃H₁₂N₅O)₂], (I), and di-μ-azido-κ⁴N¹:N¹-bis({6-methyl-N'-[1-(pyrazin-2-yl-κN¹)ethylidene]nicotinohydrazidato-κ²N',O}nickel(II)), [Cu₂(C₁₃H₁₂N₅O)₂(N₃)₂], (II), derived from 6-methyl-N'-[1-(pyrazin-2-yl)ethylidene]nicotinohydrazide (HL) and azide salts, have been synthesized. HL acts as an N,N',O-tridentate ligand in both complexes. Complex (I) crystallizes in the orthorhombic space group Pbcn and has a mononuclear structure, the azide co-ligand is not involved in crystallization and the Ni²⁺ centre lies in a distorted {N₄O₂} octahedral coordination environment. Complex (II) crystallizes in the triclinic space group P-1 and is a centrosymmetric binuclear complex with a crystallographically independent Cu²⁺ centre coordinating to three donor atoms from the deprotonated L^- ligand and to two N atoms belonging to two bridging azide anions. The two- and one-dimensional supramolecular structures are constructed by hydrogen-bonding interactions in (I) and (II), respectively. The in vitro urease inhibitory evaluation revealed that complex (II) showed a better inhibitory activity, with the IC₅₀ value being 1.32±0.4 µM. Both complexes can effectively bind to bovine serum albumin (BSA) by 1:1 binding, which was assessed via tryptophan emission-quenching measurements. The bioactivities of the two complexes towards jack bean urease were also studied by molecular docking. The effects of the metal ions and the coordination environments in the two complexes on in vitro urease inhibitory activity are preliminarily discussed.

Crystal structure of (μ-trans-1,2-bis-{2-[(2-oxido-phen-yl)methyl-idene]hydrazin-1-yl-idene}ethane-1,2-diolato-κ3O,O',N)bis-[di-tert-butyl-tin(IV)]

The binuclear complex, [Sn2(C4H9)4(C16H10N4O4)], contains two Sn4+ ions, connected by doubly N-deprotonated oxalylbis[(2-oxido-benzyl-idene)hydrazide] ligands, and each Sn4+ ion is linked to two tert-butyl groups. The coordination sphere of each Sn atom is best described as a distorted trigonal bipyramid. Each stannic ion in the complex is in a C2O2N environment. The two homologous parts of the doubly deprotonated ligand are located in trans positions with respect to the C-C bond of the oxalamide group. The oxalamide group exhibits an asymmetric coordination geometry, as seen by the slight difference between the C-O and C-N bond lengths. The three-dimensional network is a multilayer of complex mol-ecules with no strong supramolecular inter-actions.