IR-UV ion-dip spectroscopy of N-phenyl formamide, and its hydrated clusters

IR-UV ion-dip spectroscopy has been used to study N-phenylformamide and its hydrated clusters in the ground and excited (S-1) electronic states. Their NH stretch bands readily differentiate cis (3441 cm(-1)) and trans (3463 c m(-1)) isomers. Clusters of trarts-N-phenylformlamide with 1 or 2, water mo lecules show nearly equal preference for binding to the NH and CO sites. A further cluster is assigned in which a chain of four water molecules form a n H-bonded bridge between NH and CO. Its vibrational spectrum is characteri sed by broad, intense and red-shifted bands resulting from strong cooperati ve effects and distribution of vibrational motion along the II-bonded chain . (C) 2000 Elsevier Science B.V. All lights reserved.