6
M. Matsui
X
X'
X
X
R
R
X
X
X
X'
X
X'
X = NR, O, S, Se (Te)
R = H, Ph,
t-Bu
Group A (cationic)
X = NR, O, S, Se
X = NR, O, S, Se
X = NR, O, S, Se
X, X' = NR, O, S
X, X' = NR, O, S, Se
X,X' = NR, O, S, Se
N
R' R'
R
R,R' = alkyl group
N
Y
X
O
X = O, S Y = O, NR
N
N
O
X = O, S
N
N
R = alkyl group
S
O
O
R
R
X
O
O
O
X = NR, O, S
Group B (anionic)
Example of linkage group
X
X = CH, N
X
X'
O
O
O
O
O
O
O
O
O
O
Examples of heteroaromatic end rings
R
N
N
O
R
R
X, X' = CH, N
R
R
Hetero
end
aromatics
Hetero
end
aromatics
Linkage
group
1.3
Cl
Cl
Fig. 1.3
Structure of polymethine dyes