N.C.O.
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The four fluorescence peaks are generated separately by the combined actions of the methyl parathion and the acetone. In methyl parathion molecule, there are the transition of n electrons in nitryl, the transition of π electronic structure formed by the oxygen atom and the benzene ring and the transition of n electrons in P=O group. In acetone molecule, there is the transition of n electrons in C=O group.
分析得到,四处荧光峰分别是溶剂丙酮分子中C=O上的n电子跃迁、硝基上的n电子跃迁、甲基对硫磷分子中氧原子与苯环形成的大共轭π电子结构跃迁以及P=S上的n电子跃迁共同作用产生。
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In this thesis,the AM1,MNDO,MINDO/3(mainly AM1)and INDO/S-CI semiempirical MO methods were used toinvestigate the excited-state intramolecular protontransfer reactions of salicylic acid derivatives—salicylic acid,methyl salicylate,salicylaldehyde,o-hydroxyaceto-phenone,salicylamide and 3-hydroxy-picolinamide (6 conformers and 2-3 anion species);2-(2'-hydroxy-5' methylphenyl) benzotriazole(4 conformers),2-(2' hydroxyphenyl) benzimidazole (3 conformers and 3anion species),Bis-2,5-(2-benzoxazolyl)hydroquinone(3 conformers),2-(2'-hydroxyphenyl)benzothiazole(2conformers) and 7-azaindole dimer (2 conformers).Theinvestigations were described as follows.Geometry optimization,relative stability andhydrogen bonding energy First,for sylicylic acid derivative molecules,the AM1,MNDO and MINDO/3 methods were used toinvestigate ground-state geometry optimization,energies,relative stabilities and hydrogen-bondingenergies on the five kinds of the molecules(designing 6 conformers and 2-3 anion species).Comparing with experimental data,the optimizedgeometry,the order of stability,the hydrogen-bonding energies and the distances between O-O in O-H..O hydrogen bonds by AM1 method were in agreementwith the experimental data,however,the C-C bondlengths optimized by MNDO and MINDO/3 were longer,C-O and O-H bond lengths were shorter;for C-N bondlengths,the results opitimized by MNDO method werethe same as those by AM1 method,nevertheless the C-Nbond lengths given by MINDO/3 method were muchshorter.For some sylicylic acid derivatives(e.g.methyl salicylate,salicylamide),the order ofstabilities on the conformers given by MNDO andMINDO/3 methods were not in agreement with theexisting conformers deduced by experimental methods,and the hydrogen bonding energies calculated by MNDO.and MINDO/3 methods were smaller.Second,the studyon the other systems found that the optimizedgeometry of the proton-transfered product with INDOmethod could not be obtained,only could theoptimized geometry of reactant be obtained,and thecalculated hydrogen bonding energies were greater.Many results of calculation indicated that the studyon the excited-state intramolecular proton transferreaction system using AM1 method was suitable andreliable.
本论文用AM1、MNDO、MINDO/3(主要是AM1)和INDO/S-CI半经验分子轨道方法对水杨酸衍生物系列——水杨酸、水杨酸甲酯、水杨醛、O-羟基乙酰苯酮、水杨酰胺和3-羟基吡啶酰胺(6种异构体和2-3种阴离子);2-(2'-羟基-5'-甲基苯基)苯并三〓唑(4种异构体);2-(2'-羟基苯基)苯并咪唑(3种异构体和3种阴离子);2,5-二间氮杂氧茚氢醌(3种异构体);2-(2'-羟基苯基)间〓杂硫茚(2种异构体)和7-〓吲哚二体(2种异构体)的激发态分子内质子转移反应在以下几个方面进行了较系统的理论研究:几何构型优化和相对稳定性及氢键能首先以水杨酸衍生物系列分子为例,用AM1、MNDO和MINDO/3方法考察了5种分子(每种分子设计6种异构体和2-3种阴离子)的基态几何构型优化,能量、相对稳定性和氢键能计算,通过和实验数据进行比较,AM1方法给出的优化几何构型、稳定性次序、氢键能和O—H。。。O氢键的0—0距离与实验数据吻合最好,MNDO和MINDO/3方法优化的C-C键长偏长,C-O键和O-H键长偏短;对于C-N键长,MNDO和AM1优化结果差别不大,而MINDO/3给出了过短的C-N键长,MNDO和MINDO/3方法给出的有些水杨酸衍生物分子(如水杨酸甲酯和水杨酰胺)异构体的稳定性次序和实验上推测的可存在异构体结果不一致,MNDO和MINDO/3方法给出的氢键能偏低,对其他体系的研究发现INDO方法常常不能得到质子转移产物的优化几何构型,只能得到反应物的优化构型,并且估算的氢键能偏高,大量的计算结果表明AM1方法对本论文研究的激发态分子内质子转移反应体系是适宜和可靠的。
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But in the systems of HO-C≡P and NH2-C≡P, H-P=C=O and N≡C-PH2 containing C≡N triple bond are thermodynamically the most stable species, respectively.
而在HO-C≡P和NH2-C≡P体系中,热力学最稳定的结构却是H-P=C=O和含C≡N三键的N≡C-PH2。
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Security N.C.O.","Security Sergeant:安全士官
"士官长",,"First Sergeant","Master Sergeant" | "安全士官",,"Security N.C.O.","Security Sergeant" | "队长","军乐队","Company Commander&q