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Seven homologous series p-A=B-C_6H_4(CH=CH)_nX=Y (A=B: NO_2, X=Y: CHO,COMe, CN, NO_2; A=B: CN, X=Y: CHO, CN; A=B: H, X=Y: NO_2) were synthesized, theeffect of opposite terminal groups in phenylpolyenic conjugative systems has been studied by meansof UV, XPS, ~(13) C NMR and quantum chemical calculation. The results show that: 1. There exists theeffect of opposite terminal groups exists in phenylpolyenic and other aromatic conjugative systems.2. When A=B and X=Y are the same, the group (-X=Y) connected at polyenic chain is a terminalgroup, while the other is an opposite terminal group. When the two groups are different, the onewith weaker conjugative power plays the role of the opposite terminal group. 3. The effect of oppositeterminal groups increases successively in the order of CN, COMe, CHO, NO_2 and can be quantita-tively described with substitute equivalent △N_s. Theλ_(max) of compound containing an oppositeterminal group can be calculated by the homologous equation 10~(-4) =a+b/(1/2)~(2/N＇~(-S)_a), most of thecalculated values are in agreement with experiment results.
Seven homologous series pA = B-C_6H_4 (CH = CH) _nX = Y (A = B: NO_2, X = Y: CHO, COMe, CN, NO_2; A = B: CN, X = Y: CHO, CN; A = B: H, X = Y: NO 2) were synthesized, the effect of opposite terminal groups in phenylpolyenic conjugative systems has been studied by means of UV, XPS, ~ (13) C NMR and quantum chemical calculation. There exists theeffect of opposite terminal groups exists in phenylpolyenic and other around conjugative systems.2. When A = B and X = Y are the same, the group (-X = Y) connected at polyenic chain is a terminalgroup, while the other is an opposite terminal group. When the two groups are different, the one with weaker conjugative power plays the role of the opposite terminal group. 3. The effect of oppositeterminal groups increases successively in the order of CN, COMe, CHO, NO_2 and can be quantita -notally described with a substitute equivalent ΔN_s. Theλ_ (max) of compound containing an oppositeterminal group can be calculated by the homologous equation 10 -4 = a + b / (1/2) ~ (2 / N ’~ (-S) _a), most of thecalculated values are in agreement with experiment results.