METAL AND ORGANOMETAL COMPLEXES OF OXY- AND THIOPHOSPHORUS ACIDS. VIII. REACTIONS OF O,O-DIISOPROPYL AND O,O-ALKYLENE DITHIOPHOSPHORIC ACIDS WITH TITANIUM AND TIN TETRACHLORIDE

Catalytic Chemosensing Assay for Selective Detection of Methyl Parathion Organophosphate Pesticide

Herein, a catalytic chemosensing assay (CCA), based on a bimetallic complex, [Ru^II (bpy)₂ (CN)₂ ]₂ (Cu^I I)₂ (bpy=2,2'-bipyridine), is described. This complex integrates a task-specific catalyst (Cu^I -catalyst) and a signaling unit ([Ru^II (bpy)₂ (CN)₂ ]) to specifically hydrolyze methyl parathion, a highly toxic organophosphate (OP) pesticide. The bimetallic complex catalyzed the hydrolysis of the phosphate ester to generate o,o-dimethyl thiophosphate (DTP) anion and 4-nitrophenolate. Intrinsically, 4-nitrophenolate absorbed UV/Vis light at λ_max =400 nm, creating the first level of the chemosensing signal. DTP interacted with the original complex to displace the chromophore, [Ru^II (bpy)₂ (CN)₂ ], which was monitored by spectrofluorometry; this was classified as the second level of chemosensing signal. By integrating both spectroscopic and spectrofluorometric signals with a simple AND logic gate, only methyl parathion was able to provide a positive response. Other aromatic and aliphatic OP pesticides (diazinon, fenthion, meviphos, terbufos, and phosalone) and 4-nitrophenyl acetate provided negative responses. Furthermore, owing to the metal-catalyzed hydrolysis of methyl parathion, the CCA system led to the detoxification of the pesticide. The CCA system also demonstrated its catalytic chemosensing properties in the detection of methyl parathion in real samples, including tap water, river water, and underground water.

A study of a variety of O,O-alkylene dithiophosphate derivatives of triphenyl-and diphenylgermane. Crystal structures of and

The O,O-alkylene dithiophosphate derivatives of triphenyl- and diphenylgermane, [Formula: see text] [Formula: see text] [Formula: see text] [Formula: see text] [Formula: see text] and [Formula: see text] have been prepared and characterized by infrared, Raman, and 1H, 13C, and 31P NMR spectroscopy, mass spectrometry, and, in three cases, X-ray crystallography. [Formula: see text] 1, crystallizes as monoclinic in the space group P21/a (No. 14) with the cell parameters a = 12.868(5) Å, b = 11.354(4) Å, c = 17.207(4) Å, β = 95.42(2)°, V = 2502(1) Å3, Z = 4, R = 0.0640, and Rw = 0.0585. [Formula: see text] 2, crystallizes as orthorhombic in the space group Pbca (No. 61) with the cell parameters a = 23.007(4) Å, b = 16.840(4) Å, c = 12.068(3) Å, V = 4657(3) Å3, Z = 8, R = 0.0502, and Rw = 0.0329. [Formula: see text] 3, crystallizes as monoclinic in the space group C2/c (No. 15) with the cell parameters a = 35.48(2) Å, b = 9.275(5) Å, c = 20.78(1) Å, β = 120.93(3)° V = 5866(5) Å3, Z = 8, R = 0.0674, and Rw = 0.0562. As with their methylgermanium analogues, the environment about germanium is essentially that of a distorted tetrahedron, with the terminal sulfur atoms oriented towards germanium rather than away from it, in contrast with analogous noncyclic dithiophosphatogermanes. The substituents on the atoms in both the five- and six-membered rings maintain their nonequivalence in solution, in contrast with tin analogues. Keywords: structure, germanium, diphenyl, triphenyl, cyclic dithiophosphates