CAJ | 학술논문

借助密度泛函理论中B3LYP/6-311＋＋G（d ，p）方法对美国EPA优先控制污染物中的16种多环芳烃（PAHs）：萘、苊烯、苊、芴、菲、蒽、荧蒽、芘、苯并[a]蒽、稠二萘、苯并[b]荧蒽、苯并[k]荧蒽、苯并[a]芘、二苯并（a ，h）蒽、二苯并[g ，h ，i]芘以及茚苯（1，2，3-cd）芘进行结构优化，并计算拉曼光谱振动频率和去偏振度，在此基础上辨识多环芳烃的拉曼特征光谱。研究显示，16种PAHs的拉曼振动主要分布在3个频区：200～1000 cm -1（指纹区）、1000～1700和3000～3200 cm-1（基团频率区），3个频区主要振动归属分别为环变形（ring def），碳碳伸缩（CCStr）、碳氢摇摆（CHw ）及其耦合振动（CCStrCCw ），碳氢伸缩（CHStr）。进一步分析显示，指纹区16种PAHs的去偏振度随苯环变形振动对称性增强而降低，在该频区去偏振度最小的频移处苯环呼吸振动的对称性最强，指纹区的峰强也在此处出现最大值。任意PAHs在指纹区的最强峰之间的波数差较大，在显微拉曼光谱的可分辨范围内，因而利用指纹区的去偏振度和最强峰可将16种PAHs逐一识别。烷烃、烯烃、炔烃、醇类和酚类、脂肪醚、芳基烷基醚、醛类、酮类、羧酸、酯类、胺类、腈类、酰胺类、酸酐、芳烃的振动频率和峰强分布不完全一致，利用 PAHs与这几类物质拉曼频率和峰强分布的差异可以逐一排出干扰。
차조밀도범함이론중B3LYP/6-311＋＋G（d ，p）방법대미국EPA우선공제오염물중적16충다배방경（PAHs）：내、액희、액、물、비、은、형은、비、분병[a]은、주이내、분병[b]형은、분병[k]형은、분병[a]비、이분병（a ，h）은、이분병[g ，h ，i]비이급인분（1，2，3-cd）비진행결구우화，병계산랍만광보진동빈솔화거편진도，재차기출상변식다배방경적랍만특정광보。연구현시，16충PAHs적랍만진동주요분포재3개빈구：200～1000 cm -1（지문구）、1000～1700화3000～3200 cm-1（기단빈솔구），3개빈구주요진동귀속분별위배변형（ring def），탄탄신축（CCStr）、탄경요파（CHw ）급기우합진동（CCStrCCw ），탄경신축（CHStr）。진일보분석현시，지문구16충PAHs적거편진도수분배변형진동대칭성증강이강저，재해빈구거편진도최소적빈이처분배호흡진동적대칭성최강，지문구적봉강야재차처출현최대치。임의PAHs재지문구적최강봉지간적파수차교대，재현미랍만광보적가분변범위내，인이이용지문구적거편진도화최강봉가장16충PAHs축일식별。완경、희경、결경、순류화분류、지방미、방기완기미、철류、동류、최산、지류、알류、정류、선알류、산항、방경적진동빈솔화봉강분포불완전일치，이용 PAHs여저궤류물질랍만빈솔화봉강분포적차이가이축일배출간우。
In the present paper ,by means of density functional theory in B3LYP/6-311+ +G(d ,p) method ,16 kinds of pollu-tants ,i .e .polycyclic aromatic hydrocarbons (PAHs):naphthalene (Nap) ,acenaphthylene (AcPy) ,acenaphthene (Acp) ,flu-orene (Flu) ,phenanthrene (PA) ,anthracene (Ant) ,fluoranthene (Fl) ,pyrene (Pyr) ,benzo [a] anthracene (BaA) ,fused two naphthalene (CHR) ,benzo [b] fluoranthene (BbF) ,benzo [k] fluoranthene (BkF) ,benzo [a] pyrene (BaP) ,dibenzo (a ,h) anthracene (DahA) ,dibenzo [g ,h ,i] pyrene (BghiP) and indene benzene (1 ,2 ,3-cd) pyrene (IcdP) among the U .S .EPA priority pollutants were selected ,whose structures were optimized and Raman vibrational frequencies and depolarization were cal-culated .The structure ,Raman vibrational frequencies and depolarization were basis of identification of PAHs .Studies have shown that Raman vibrations of 16 PAHs are mainly distributed in three frequency regions:200~1 000 cm -1 (fingerprint re-gion) ,1 000~1 700 cm -1 and 3 000~3 200 cm -1 (group frequency region) ,corresponding vibrations were assigned to ring de-formation (ring def) ,C-C stretching (CCStr) ,C- H wiggle (CHw ) and of these two patterns (CCStrCCw ) ,and C-H stretching (CHStr) .Further analysis showed that in fingerprint region the depolarization of 16 PAHs was reduced with the sym-metry of benzene deformation vibration enhanced .At the point of minimum depolarization ,symmetry and Raman peak of benzene ring breathing vibration were found strongest .At the minimum differential wave number the strongest peak in fingerprint region was distinguishable by micro-Raman spectroscopy .Therefore ,16 PAHs can be individually identified by depolarization and the strongest peak in fringerprint region .Vibration frequencies and peak intensity distribution of alkanes (Akn) ,olefin (Oe) ,al-kyne (Aye) ,alcohols and phenols (Aap) ,aliphatic ether (Ape) ,arylalkyl ether (Aae) ,aldehydes (Ahd) ,ketones (Ktn ) ,car-boxylic acid (Cba) ,esters (Etr) ,amines (Aie) ,nitriles (Nte) ,amides (Aid) ,acid anhydride (Ahr) ,aromatic hydrocarbons (Ahc) were not completely consistent with each other ,and interference can be discharged by the differences of frequency and peak intensity distribution .