Mass spectrometer vacuum-lock carriages coated with Teflon-S

Metallosupramolecular Structures Derived from a Series of Diphosphine-bridged Digold(I) Metalloligands with Terminald-Penicillamine

“…The C5O stretching bands of [H 2 1]-[H 2 5] in the infrared spectra appear at approximately 1625-1628 cm 21 , which is typical for zwitterionic amino acids (NH 1 3 -R-COO -) (1620-1630 cm 21 ), but not nonionized ones (NH 2 -R-COOH) (1700-1730 cm 21 ). [46] Thus, D-Hpenin [H 2 1]-[H 2 5] is assumed to exist in a zwitterionic form with protonated amine and deprotonated carboxyl groups, such as free D-H 2 pen [47] and NH 4 [Au(D-Hpen-S) 2 ]. [15] Three of the five metalloligands ([H 2 2], [H 2 3], [H 2 4]) were characterized by single-crystal X-ray crystallography ( and [H 2 4], which contain two and four methylene groups, respectively, adopt anti-orientation with respect to the twoterminal D-pen moieties, whereas [H 2 3], which contains three methylene groups, exhibits syn-orientation.…”