The INDO series of methods were used to optimize the structures of C n 76(-4≤n≤6) without any symmetry constriction. It was indicated that there are 30 kinds of bonds and 19 types of unique carbon atoms, but there a...The INDO series of methods were used to optimize the structures of C n 76(-4≤n≤6) without any symmetry constriction. It was indicated that there are 30 kinds of bonds and 19 types of unique carbon atoms, but there are not Jahn Teller distortion in C n 76, which is different from C n 60 and C n 70. Furthermore, the C n 76 ions are less stable than C 76. Based on the optimized geometries, the electronic spectra were calculated by INDO/SCI method. It was shown that the NIR absorptions for C n 76 singlet will appear beyond \{1 000\} nm. Electronic transition was assigned theoretically and the reason of red shift for absorption peaks of C n 76 compared with those of C 76 was discussed.展开更多
Twenty-tow possible isomers for C76BN were studied by INDO methods. The two most stable geometries are 52,53-C76BN and 29,28-C76BN, in which boron and nitrogen atoms are connected with each other and located at the 6/...Twenty-tow possible isomers for C76BN were studied by INDO methods. The two most stable geometries are 52,53-C76BN and 29,28-C76BN, in which boron and nitrogen atoms are connected with each other and located at the 6/6 bond near the longest axis of C78（C2v）. Electronic spectra of C76BN were investigated with INDO/SCI method. UV absorptions of C76BN are red-shifted compared with those of Crs（C2v）. The structures and IR spectra for the four stable isomers of C76BN were calculated by AM1 method. It was indicated that the substitution of the BN unit weakens the conjugation of carbon atoms, leading to the decrease of IR frequencies.展开更多
Study of geometries of 16 possible isomers for C76N2 based on C78(C2v) by intermediate neglect of differential overlap (INDO) series of methods indicated that the most stable geometry 25,78-C76N2 where two nitrogen at...Study of geometries of 16 possible isomers for C76N2 based on C78(C2v) by intermediate neglect of differential overlap (INDO) series of methods indicated that the most stable geometry 25,78-C76N2 where two nitrogen atoms substitute two apexes C(25) and C(78) near the shortest X axis and Y axis formed by two hexagons and a pentagon. Electronic structures and spectra of C76N2 were investigated. The reason for the red-shift for absorptions of C76N2 compared with that of C78(C2v) is discussed.展开更多
文摘The INDO series of methods were used to optimize the structures of C n 76(-4≤n≤6) without any symmetry constriction. It was indicated that there are 30 kinds of bonds and 19 types of unique carbon atoms, but there are not Jahn Teller distortion in C n 76, which is different from C n 60 and C n 70. Furthermore, the C n 76 ions are less stable than C 76. Based on the optimized geometries, the electronic spectra were calculated by INDO/SCI method. It was shown that the NIR absorptions for C n 76 singlet will appear beyond \{1 000\} nm. Electronic transition was assigned theoretically and the reason of red shift for absorption peaks of C n 76 compared with those of C 76 was discussed.
文摘Twenty-tow possible isomers for C76BN were studied by INDO methods. The two most stable geometries are 52,53-C76BN and 29,28-C76BN, in which boron and nitrogen atoms are connected with each other and located at the 6/6 bond near the longest axis of C78（C2v）. Electronic spectra of C76BN were investigated with INDO/SCI method. UV absorptions of C76BN are red-shifted compared with those of Crs（C2v）. The structures and IR spectra for the four stable isomers of C76BN were calculated by AM1 method. It was indicated that the substitution of the BN unit weakens the conjugation of carbon atoms, leading to the decrease of IR frequencies.
文摘Study of geometries of 16 possible isomers for C76N2 based on C78(C2v) by intermediate neglect of differential overlap (INDO) series of methods indicated that the most stable geometry 25,78-C76N2 where two nitrogen atoms substitute two apexes C(25) and C(78) near the shortest X axis and Y axis formed by two hexagons and a pentagon. Electronic structures and spectra of C76N2 were investigated. The reason for the red-shift for absorptions of C76N2 compared with that of C78(C2v) is discussed.
