Eco-friendly synthesis of silver nanoparticles and its larvicidal property against fourth instar larvae of Aedes aegypti.

In this study, larvicidal activity of silver nanoparticles (AgNPs) synthesised using apple extract against fourth instar larvae of Aedes aegypti was determined. As a result, the AgNPs showed moderate larvicidal effects against Ae. aegypti larvae (LC50 = 15.76 ppm and LC90 = 27.7 ppm). In addition, comparison of larvicidal activity performance of AgNPs at high concentration prepared using two different methods showed that Ae. aegypti larvae was fully eliminated within the duration of 2.5 h. From X-ray diffraction, the AgNP crystallites were found to exhibit face centred cubic structure. The average size of these AgNPs as estimated by particle size distribution was in the range of 50-120 nm. The absorption maxima of the synthesised Ag showed characteristic Ag surface plasmon resonance peak. This green synthesis provides an economic, eco-friendly and clean synthesis route to Ag.

Dichlorido{N,N-dimethyl-N'-[1-(2-pyrid-yl)ethyl-idene]ethane-1,2-diamine-κN,N',N''}copper(II).

In the title compound, [CuCl(2)(C(11)H(17)N(3))], the Cu(II) ion is five-coordinated with a distorted square-pyramidal configuration. The three N atoms of the Schiff base ligand and one Cl atom are located in the basal plane, whereas the other Cl atom is apically positioned.

(1R,2R)-N,N'-Bis[1-(2-pyrid-yl)ethyl-idene]cyclo-hexane-1,2-diamine.

In the title compound, C(20)H(24)N(4), the cyclo-hexane ring adopts a chair conformation with the two imine groups linked at equatorial positions. The two halves of the mol-ecule are related by a crystallographic twofold rotation axis. The dihedral angle between the pyridine rings is 75.73 (3)°.

Bis[µ-4-hydr-oxy-N'-(4-meth-oxy-2-oxido-benzyl-idene)benzohydrazidato]bis-[pyridine-copper(II)].

In the title compound, [Cu(2)(C(15)H(12)N(2)O(4))(2)(C(6)H(5)N)(2)], each Cu(II) atom is chelated by the tridentate doubly deprotonated Schiff base and a pyridine mol-ecule in a nearly planar environment (r.m.s. deviation for all non-H atoms = 0.107 Å). The metal ions are bridged by one O atom from the symmetry-related Schiff base ligands, forming a centrosymmetric dinuclear copper(II) complex. The dimeric complex is linked to another dimer via weaker Cu-O inter-actions and also O-H⋯N hydrogen bonds.