Spectroscopy of jet-cooled tyrosine derivatives

Abstract

Using fluorescence-based techniques (excitation and emission spectra lifetimes), we have studied the jet-cooled tyrosine derivatives tyramine and 3-(4-hydroxyphenyl) propionic acid (HPA). For solvent addition resulting in small, mainly one adduct complexes, there is a high degree of analogy with the results for the corresponding analogs of the amino acid tryptophan. In particular, for tyramine, as had been the case with its tryptophan analog tryptamine, addition of one -OH bearing solvent molecule at the α-amine apparently results in a complex in a single conformation.

Hydrated Clusters of 2-Phenylethyl Alcohol and 2-Phenylethylamine: Structure, Bonding, and Rotation of the S1 ← S0 Electronic Transition Moment

“…An effective "Boltzmann temperature" of a few hundred kelvin may be implied, although it is questionable whether the concept of equilibrium may be applied to complex formation in a jet expansion. Alternative 1:1 water complexes of tyramine have been observed previously, 9 although they were associated with binding to different functional groups (phenolic OH and alkyl NH 2 ).…”

“…In both 3-phenylpropionic acid 3 and its p -hydroxy derivative, 1:1 clusters are observed in which water binds as a proton acceptor to the acid group, red-shifted by ca. 10 cm -1 relative to the corresponding monomer feature.…”

“…Supersonic jet spectroscopy provides an excellent means of isolating and identifying different conformers of flexible organic molecules and studying the structure and energetics of their solvated clusters. − Recent studies, conducted at very high resolution in Pratt's laboratory 1,2 and at lower resolution in our own, − have focused on rotational band structure for S 1 ← S 0 electronic transitions to assign conformers in a range of substituted aromatic molecules. The band contours are distinguished not only by inertial axis differences but also by strong, conformationally induced changes in the alignment of the S 1 ← S 0 transition moment (TM).…”

Revised conformational assignments and conformational evolution of tyrosine by laser desorption supersonic jet laser spectroscopy

“…amino-acid, is indispensable. In particular, the conformation of aromatic amino-acids, phenylalanine (Phe), [2][3][4][5][6][7][8][9][10][11] tyrosine (Tyr) [2][3][4]9,10,[12][13][14][15][16][17][18][19][20][21][22][23] and tryptophan, [24][25][26][27][28][29] has been investigated since the early days of supersonic jet spectroscopy.…”

The R2PI Spectroscopy of Tyrosine: A Vibronic Analysis

“…With the goal of identifying some of the physical properties that cause these neurotransmitters to exhibit their interesting biological behavior, we have been studying the vibronic spectroscopy of families of structurally related compounds. The spectroscopy of tyrosine has been studied fairly extensively, both in the ground state (1,2) and for electronic transitions (3)(4)(5). As far as we can tell, however, no one has yet made a complete assignment for the ground-state vibrations or for the vibronic transitions between the ground and first excited electronic states.…”