A Group Theoretical and Quantum Chemical Study of Electronic Absorption and Fluorescence, Vibrational Spectra, and Conformations of Trimethine Cyanine Dye Molecules

Table 2

Symmetric vibrations of the molecule (I).

Number	Frequency,; cm^−1	Localization of vibrations	Intensity
1	70	Two polynomial carried pendulum oscillations, changing the angle of the C-C-C-center	0.049
2	300	Folding: fragments move forward; methine bridge changes the angles	0.078
3	405	Methine bridge and ring in antiphase	0.011
4	829	Synchronous changing of angles O-C-N and central C-C-C	0.29
5	927	Vibrations angle O-C-C in rings	2.1
6	1067	Vibrations of methine angles bond and length O-C-N	0.084
7	1147	Pendulum oscillations of C-H groups in the rings	24
8	1196	Vibrations of the molecule along -axis.	0.23
9	1280	Vibrations lengths S-O-S	2.5
10	1320	Pendulum oscillations of N-H are accompanied by vibrations of the bonds and the methine bridge	2.0
11	1325	Symmetric pendulum vibrations of C-H bonds bridge	2.4
12	1418	Vibrations rings along ; central heating C atoms along .	0.63
13	1512	Horizontal vibrations C-N	0.096
14	1590	The length of the C-N and C-C-C	16
15	1686	C-C rings	3.8
16	1864	Bonds rings with the methine bridge	44
17	3129	All three groups C-H bridge in antiphase with the central C-H	17
18	3162	All three C-H groups in the bridge phase	70
19	3207	Two upper C-H bonds in the ring	150
20	3254	Two lower C-H bonds in the ring	53
21	3497	Two N-H- bonds	180