O
/ \ ‖
. // \__ C
| │| > O
| │|__ C
. \\ /. ‖
\ / .O
phthalic acid
o-phthalic acid
. OH
│
. O=C
│
/ \
. // \
| │|
| │|_ C _ OH
. \\ /. ‖
\ / .O
isophthalic acid
m-phthalic acid
. O ____ O
‖ // ヽヽ. ‖
OH _ C _//. ヽヽ_ C _ OH
ヽ /
ヽ.ニニ./
terephthalic acid
p-phthalic acid
. O ____ O
‖ // ヽヽ. ‖
HO _ C _//. ヽヽ_ C _ OH
ヽ /
ヽ.ニニ./
. O
/ \ ‖
. / \\__. C
| | | > O
| | |__ C
. \ // ‖
\ / O