Theoretical Study On Chemiluminescence Reagent Of Luminol

Hydrazine derivatives are a class of organic compounds with highreaction activity; so far, a large number of single and binarysubstituted hydrazide derivatives were synthesized and to studied.Luminol as the representative material of hydrazideschemiluminescence reagent, the much attention has been paid to theresearch and application of chemiluminescence. Modified thearomatic ring of luminol compounds can generally producechemiluminescence reaction. From the theory calculation to studyluminol derivatives properties between structure and electronicspectra, expected to be found a molecular with good luminescenceproperties, and further broaden the application range of this kind ofcompounds.This paper mainly used the theoretical calculation methods toinvestigate the structure, frontier molecular orbital and electronicabsorption spectra of the luminol derivatives. The specific researchcontents are as follows:1. In this research, geometrical optimisation, Mulliken charge,molecular electrostatic potential, and the frontier molecular orbitalsof three dimethoxy-substituted luminol derivatives were investigatedby ab initio, density functional, and M ller-Plesset perturbation theory with a6-311G (d, p) basis set in gas phase, water, anddimethylsulphoxide solution. The UV-vis spectra were calculated bytime dependent density functional theory method. The properties ofderivatives were compared with luminol at a molecular level toinvestigate the change induced by the methoxy group. The threederivatives were also compared with the aim of predicting the orderof chemiluminescent efficiency. The results showed that methoxysubstitution significantly changed the electronic and spectralproperties of luminol. Among three derivatives, structure2wassuggested to have the highest chemiluminescent efficiency. Theresults may shed some light on the design and selection ofchemiluminescent reagents.2. The geometries of phthalhydrazide and phthalhydrazide-relatedcompounds are optimized at the B3LYP level using6-311G (d, p) basisset in gas phase, water, and dimethylsulphoxide solution. The resultsshow that after introduced a nitrogen containing substituent on thebenzene ring of phthalhydrazide, the N-H bond lengths of compoundsare longer, are conducive to the chemiluminescence reaction. Fromthe analysis of the frontier molecular orbitals, the energy gap ofcompound9(3.273531ev) is minimum, it is the most active. TD-DFTtheoretical method is used to simulate the UV absorption spectra ofphthalhydrazide and phthalhydrazide-related compounds in gas phase,water phase and dimethylsulphoxide solution. The maximumabsorption wavelength has red shift for the modifications of thebenzoylhydrazine derivatives. Substituent group of Compound9makes molecule conjugate enhanced, the maximum absorptionwavelength is largest. 3. The present paper provides the properties forchemiluminescence of luminol-type compounds by quantum chemicalcalculation. Luminol related compounds of7-amino-6-sulfanylphthalazine-1,4(2H,3H)-dione (ASPH) and its sixderivatives have been investigated. The chemiluminescenceproperties were compared with the standard luminol and ASPH. Thebond length of chemiluminescence site of the ASPH and ASPH-relatedcompounds were found different and it changed smaller for it is faraway the substitutes. The energy gaps of all ASPH derivatives aresmaller than ASPH. The compound of PY-ASPH with smallest energygap and maximum absorption wavelength in water and DMSO solutionis selected as the best chemiluminescence compounds.