CAJ | 학술논문

测量了2-烷基TCNQ(C_8TCNQ,C_(12)TCNQ,C_(18)TCNQ)浇铸膜的红外光谱,发现这类化合物的红外CH_2剪式振动在1 471和1 462 cm~(-1)处显示2个峰.这2个峰的强度比(I_(1471)/I_(1462))随着烷基链的长度增加而明显减少.另外,来自CH_2的1 471 cm~(-1)吸收峰与来自TCNQ环的1 529 cm~(-1)吸收峰的相对强度随着碳链的长度增加而不发生变化.CnTCNQ系列化合物的红外光谱CH_2的剪式振动行为与长链脂肪酸中CH_2行为很不相同.在长链脂肪酸中,晶体场效应导致了剪式振动分裂.考虑C_(12)TCNQ的晶体结构,而将1 471cm~(-1)峰归属为非叉指对接的碳链,将1 462 cm~(-1)峰归于叉指对接的碳链,双峰的出现与晶体场分裂无关.并且得到烷基TCNQ中,非叉指对接的碳链的长度与碳链总长度无关的结论.
측량료2-완기TCNQ(C_8TCNQ,C_(12)TCNQ,C_(18)TCNQ)요주막적홍외광보,발현저류화합물적홍외CH_2전식진동재1 471화1 462 cm~(-1)처현시2개봉.저2개봉적강도비(I_(1471)/I_(1462))수착완기련적장도증가이명현감소.령외,래자CH_2적1 471 cm~(-1)흡수봉여래자TCNQ배적1 529 cm~(-1)흡수봉적상대강도수착탄련적장도증가이불발생변화.CnTCNQ계렬화합물적홍외광보CH_2적전식진동행위여장련지방산중CH_2행위흔불상동.재장련지방산중,정체장효응도치료전식진동분렬.고필C_(12)TCNQ적정체결구,이장1 471cm~(-1)봉귀속위비차지대접적탄련,장1 462 cm~(-1)봉귀우차지대접적탄련,쌍봉적출현여정체장분렬무관.병차득도완기TCNQ중,비차지대접적탄련적장도여탄련총장도무관적결론.
Infrared (IR) spectra were measured for 2-octyl-, 2-dodecyl-, and 2-octadecyl-7, 7,8, 8-tetracyanoquinodimethane (C_8TCNQ, C_(12)TCNQ and C_(18)TCNQ) in cast films, and it was found that each spectrum shows two components for the CH_2 scissoring hand at 1 471 and 1 462 cm~(-1). Polarized IR measurements showed that the micro-crystallites in the cast films take a random orientation in the plane of the plate. The intensity ratio of the two bands at 1 471 and 1 462 cm~(-1) (I_(1471)/I_(1462)) decreases observably with the increase in the length of the alkyl chain. Moreover, the relative intensity of the 1 471 cm~(-1) CH_2 hand to a band at 1 529 cm~(-1)(C=C stretching mode of the TCNQ chromophore ring) does not change significantly for the three kinds of C_nTCNQ while the relative intensity of the 1 462 cm~(-1) CH_2 band to the band at 1 529 cm~(-1) increases markedly with the length of the alkyl chain. The above variations of the CH_2 scissoring doublet of C_nTCNQ are quite different from those of long-chain fatty acids (stearic acid and lignoceric acid) where the splitting of the CH_2 scissoring vibration occurs due to a crystal field split-ting. Considering the crystal structure of C_(12)TCNQ and the above spectral variations, the authors assign the two components of the CH_2 scissoring bands at 1 462 and 1 471 cm~(-1) of the C_nTCNQ cast films to the interdigitated and non-interdigitated parts of the alkyl chains, respectively. Furthermore, the conclusion that the length of the non-interdigitated part of the alkyl chain is al-most unchanged in the three kinds of even-numbered C_n TCNQ could also be reached.