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时间:2020-03-26
《NFeN结构和性质及反应势能曲线.pdf》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、物理化学学报(WuliHuaxueXuebao)1346ActaP.一Chim.Sin.2011,27(6),1346-1356June[Article】、^,、^rⅥ,.whxb.pku.edu.cnNFeN结构和性质及反应势能曲线蔡跃飘王朝杰(温州医学院药学院,浙江温州325035)摘要:用B3LYP/6.311+G(d)方法对化合物NFeN弯曲型和直线型的不同自旋多重度多个电子态的几何结构、电子结构、能量和振动光谱进行了计算研究.结果表明,单重态中Fe—N键长普遍比三重态和五重态中的短,在155pm左右:NFeN三重态电子结构最
2、丰富,自然键轨道和Mulliken布居显示Fe—N键具有部分离子键特征;两种结构的所有稳定态中能量最低的是1态,能量相近的有1。B、1、1。B2和1’肖态,直线型中能量最低是。态:相对于分子基态反应物Fe(aD)+N(嚣)所有电子态的能量都偏高,该反应在热力学上是不利的,但是对于原子态反应物Fe(aD)+2N(S)则是放热反应;计算振动频率和强度与实验较吻合的是1。8态;复合物FeN与化合物NFeN结构差异明显:Fe原子直接插入N分子的势能曲线表明该反应能垒很高,在动力学上也是不利的.关键词:密度泛函理论:铁原子:氮分子:二氮化铁中图
3、分类号:O641StructuresandPropertiesofNFeNandtheReactionPotentialEnergyCurvesCAlYue—Piao\/\fANGChao.Jie(SchoolofPharmacy,WenzhouMedicalCollege,Wenzhou325035,ZhejiangProvince,PR.China)Abstract:ThegeometricaIstructures,electronicstructures,energeticsandvibrationaIfrequenciesof
4、bentandIinearNFeNmoleculeswithdifferentspinmultiplicitieswerestudiedattheB3LYP/6-311+G(d1leveI.Wefindthat:(1)theFe—NbondlengthiSabout155pmforsingletstatesandthisiSshorterthanthoseintripletsandinquintets;(2)theelectronicstructuresoftripletbentNFeNaremorecomplicatedthanth
5、atoftheothers.NaturaIbondingorbitaIandMullikenpopulationdataindicatethattheFe—Nbonddisplaysionicity;(3)themoststableelectronicstateamongalthestatesis12andtheenergiesof1。B1,12,1。B2,and1’A1aresimilar,however,themoststableelectronicstateofIinearNFeNiS。厶.ThisreactioniSendot
6、hermicbecausetheenergiesofallthestatesarehigherthanthoseofthegroundstateFe(aD1+N2()reactantswhileFe(aD)+2N(S)isexothermic;(4)accordingtothecalculatedstructureandvibrationaIcharacteristicsthe1。B1statemightbeobservedinthereportedexperiments;(5)comparedwithourpreviousresul
7、tsthestructuresoftheFeN2complexesareverydiferentfr0mthatoftheNFeNcompound;(6)theFeatomdirectinsertionreactionintothetriplebondsofN2iSespeciallydi仟icultbecauseoftheenergybarriersinthereactionpotentialenergycurves.KeyWords:Densityfunctionaltheory;Ironatom;Nitrogenmolecule
8、;NFeNReceived:February24,2Ol1:Revised:March21,20l1:PublishedonWeb:April11,2Ol1.Correspondingauthor.Email:chjwa
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