Synthesis, characterization, and liquid injection field desorption ionization mass spectrometry analysis of pincer ligated group 6 (Cr, Mo, W) carbonyl complexes.

We report the synthesis of molybdenum and tungsten bromo dicarbonyl complexes (POCOP t Bu )M II Br(CO) 2 (M  =  Mo or W; POCOP t Bu   =  κ 3 -C 6 H 3 -1,3-[OP( t Bu) 2 ] 2 ) supported by an anionic PCP pincer ligand, and the chromium complex (PNP t Bu )Cr 0 (CO) 3 (PNP t Bu   =  2,6-bis(di- tert -butyl-phosphinomethyl)pyridine) bearing a neutral PNP pincer scaffold. The three group six complexes described in this study have been characterized by Liquid Injection Field Desorption Ionization Mass Spectrometry (LIFDI-MS), NMR, and IR spectroscopy. Single crystal X-ray diffraction studies show the Mo II and W II complexes adopt a six-coordinate distorted trigonal prismatic geometry, whereas the Cr 0 complex exhibits a distorted octahedral geometry.