3982-97-6Relevant academic research and scientific papers
Synthesis and kinetics of sterically altered photochromic dithizonatomercury complexes
Alabaraoye, Ernestine,Von Eschwege, Karel G.,Loganathan, Nagarajan
, p. 10894 - 10901 (2015/02/19)
Following a previous study where 12 electronically altered dithizones were synthesized, here we report on attempts to synthesize 26 dithizones. The purpose was to explore the boundaries within which dithizones may be synthesized, explore spectral tuning possibilities, and investigate steric effects on the photochromic reaction of its mercury complexes. Contrary to expectation, large substituents like phenoxy groups increased the rate of the photochromic back-reaction. In the series H-, 2-CH3-, 4-CH3-, 3,4-(CH3)2-, 2-OC6H5-, and 4-OC6H5-dithizonatophenylmercury(II), the lowest rate of 0.0004 s-1 was measured for the 2-CH3 complex, while the rate for the 2-OC6H5 derivative was 20 times higher. A solvent study revealed a direct relationship between dipole moment and the rate of the back-reaction, while the relationship between temperature and rate is exponential, with t1/2 = 2 min 8 s for the 4-phenoxy complex. The crystal structures of two dithizone precursors, 2-phenoxy- and 4-phenoxynitroformazan, are reported. (Figure Presented).
Synthesis and kinetics of electronically altered photochromic dithizonatophenylmercury(II) complexes
Von Eschwege, Karel G.
, p. 159 - 166 (2013/03/13)
A series of phenyl-substituted dithizones were synthesized, and preparation of the corresponding series of photochromic phenylmercury(II) complexes is for the first time reported. Adaption of previous methods enhanced synthesis convenience and product yields. A single crystal X-ray data collection of the ortho-S-methyl nitroformazan reaction intermediate was done. ADF computed molecular orbitals of the title compound show the HOMO and LUMO orbitals stretching along the entire ligand. The spontaneous back reaction kinetics of dithizonatophenylmercury(II) was studied at varied concentrations, temperatures and in different solvents. An exponential correlation was found between the rate of reverse isomerization and temperature, while increased solvent polarity and decreased molar mass facilitate higher return rates. The kinetic study of the series of twelve electronically altered complexes yielded a lowest rate of 0.0002 s-1 for the ortho-methyl derivative, while the highest rate of 0.0106 s-1 was measured for the meta-methoxy derivative.
