Publication Date:
2011-08-19
Description:
Six N-substituted [ n ]cyclacene ( n = 5, 6, 7,…,10) molecules were designed to study the relationship between the structure and first hyperpolarizability. Their static first hyperpolarizabilities ( β 0 ) were obtained by MP2/6-31 + g(d) level. Two interesting relationships between the β 0 value and the structure have been found: (1) The β 0 value increases with the increase of the number n when n is odd: 3155 ([5]cyclacene) 〈 48,905 ([7]cyclacene) 〈 〈 393,444 ([9]cyclacene), and when n is even: 357,620 ([6]cyclacene) 〈 618,608 ([8]cyclacene) 〈 3,513,644 a.u. ([10]cyclacene). (2) The β 0 values (in the range of 357,620 ~ 3,513,644 a.u.) of the N-substituted [ n ]cyclacene (when n is odd) are much larger (in the range of 3155~393,444 a.u.) than that of the N-substituted [ n ]cyclacene (when n is even). Furthermore, their frequency-dependent β (−2ω; ω, ω) and β (−ω; ω, 0) (ω = 0.005, 0.01, and 0.0239 a.u.) were also estimated by Møller–Plesset perturbation/6-31 + g(d) level. Among the frequency-dependent β (ω), [10]cyclacene has the largest β (−ω; ω, 0) and β (−2ω; ω, ω) to be 1.2 × 10 8 (ω = 0.01) and 2.9 × 10 7 a.u. (ω = 0.005 a.u.), which are much larger than the static β 0 = 3.5 × 10 6 a.u. by 34 and 8 times. Our present work may offer a new idea in the design of high-performance tubiform nonlinear optical materials. Copyright © 2011 John Wiley & Sons, Ltd. Because of the structure similar to famous carbon nanotubes, the N-substituted [ n ]cyclacene ( n = 5, 6…10) are chosen to investigate that how does the relationship between the structure and first hyperpolarizability ( β 0 ).
Print ISSN:
0894-3230
Electronic ISSN:
1099-1395
Topics:
Chemistry and Pharmacology
,
Physics
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