Mass spectrometry (MS) of 'carbonylated proteins' often involves derivatization of reactive carbonyl groups to facilitate their enrichment, identification and quantification. Among the many reported reagents, 2,4-dinitrophenylhydrazine (DNPH), biotin hydrazide (BHZ) and O-(biotinylcarbazoylmethyl) hydroxylamine (ARP) are the most frequently used. Despite their common use in carbonylation resear...

The octa-hedral coordination of the Cr(0) atom in the title compound, [Cr(C(20)H(24)N(2))(CO)(4)], displays some distortion. This is manifested by an exocyclic torsion angle C(mesitylene)-N-Cr-C(carbon-yl) that deviates by more than 20° from planarity. Another structural feature is the significant distortion from linearity of the Cr-C-O angles of the two carbonyl groups that inter-act with both...

The mol-ecular conformation of the title compound, C(18)H(18)O(5), is stabilized by a strong intra-molecular hydrogen bond between the hydroxyl and carbonyl groups. The C=C double bond displays an E configuration while the carbonyl group shows an S-cis configuration relative to the double bond. The dihedral angle between the two rings is 15.0 (1)°.

In the title compound, C(28)H(30)N(2)O(2), the cyclo-hexene ring system adopts a sofa conformation. The crystal structure is stabilized by C-H⋯O inter-actions between methyl H atoms of the ethyl substituents and the O atoms of carbonyl groups of adjacent mol-ecules, and by an inter-molecular carbon-yl-carbonyl inter-actions [3.207 (2) Å].

The title compound, C(13)H(12)N(2)O(2)S, crystallizes with two independent mol-ecules in the asymmetric unit. The two mol-ecules differ in the conformation of the thio-carbonyl and carbonyl groups, and show the typical geometric parameters of substituted thio-urea derivatives. The crystal structure is mainly stabilized by inter-molecular N-H⋯O hydrogen bonding.