Structural Modification Influences the Characteristics of Langmuir Monolayers from Aromatic Carboxylic Acids.
The molecular organization of purely aromatic, polyphenyl carboxylic acids, as Langmuir monolayers at the air/water interface, has been investigated by means of surface pressure and electric surface potential measurements upon film compression. The monolayer characteristics of the basic compound, a symmetrical triphenylbenzene (5'-phenyl-m-terphenyl) ring with a carboxylic group at the 4 position (namely 5'-phenyl-1,1' : 3',1"-terphenyl-4-carboxylic acid), are compared with those of its derivatives containing hydrophilic (nitro) or hydrophobic (phenyl) substituents. The nature of the substituent as well as its position (2' or 4') has a profound influence on the monolayer properties. The results are discussed in view of molecular orientation deduced from values of effective dipole moments. Copyright 2001 Academic Press.
Dynarowicz-L&acedil;tka
P.
P
Faculty of Chemistry, Jagiellonian University, Ingardena 3, Kraków, 30-060, Poland
Kita
K.
K
Milart
P.
P
Dhanabalan
A.
A
Cavalli
A.
A
da Silva Filho
D. A.
DA
Oliveira
O. N.
ON