Transition-Metal Complexes Containing Parent Phosphine or Phosphinyl Ligands and Their Use as Precursors for Phosphide Nanoparticles

P–H functional
transition-metal complexes were synthesized without using hazardous
PH3 gas in good yields by photolysis of the transition-metal
carbonyl complexes M­(CO)6‑x (M
= Cr, W, Fe; x = 0, 1) in tetrahydrofuran followed
by reaction with P2(SiMe3)4 and subsequent
methanolysis to give the bridging complexes [(CO)xM­(μ-PH2)]2 (M = Fe, x = 3 (1), M = Cr, x = 4 (2a), M = W, x = 4 (2b)). The photolysis
of [(CO)4M­(μ-PH2)]2 (M = Cr
(2a), M = W (2b)) with P­(SiMe3)3 was applied followed by methanolysis to synthesize
the PH2 bridging transition-metal binuclear complexes with
terminal PH3 groups. The products [(CO)4M­(μ-PH2)2­M­(CO)3(PH3)] (M =
Cr (3a), M = W (3b)) and [(CO)4W­(μ-PH2)2W­(CO)2(PH3)2] (4b) were isolated in moderate
yield. Another synthetic approach to this type of compounds is the
direct photolysis of the complexes [(CO)3M­(PH3)3] (M = Cr (5a), M = W (5b)).
The products were comprehensively characterized by 31P
NMR and IR spectroscopy as well as by X-ray structural analysis. Additionally,
the relevancy of 2a as single source precursor for the
synthesis of stoichiometry-controlled CrP nanoparticles has been demonstrated.

本研究通过将过渡金属羰基配合物M(CO)₆₋ₓ（M = Cr、W、Fe；x = 0、1）在四氢呋喃（tetrahydrofuran）中进行光解，随后与四(三甲基硅基)二磷[P₂(SiMe₃)₄]反应并经甲醇解，在不使用有毒磷化氢（PH₃）气体的条件下，以良好收率合成了P-H键官能化过渡金属配合物，得到桥联配合物[(CO)ₓM(μ-PH₂)]₂（M = Fe、x = 3（化合物1）；M = Cr、x = 4（2a）；M = W、x = 4（2b））。
将配合物[(CO)₄M(μ-PH₂)]₂（M = Cr（2a）、M = W（2b））与三(三甲基硅基)膦[P(SiMe₃)₃]进行光解反应后再经甲醇解，可合成带有端基磷化氢配体的PH₂桥联过渡金属双核配合物。所得产物[(CO)₄M(μ-PH₂)₂M(CO)₃(PH₃)]（M = Cr（3a）、M = W（3b））及[(CO)₄W(μ-PH₂)₂W(CO)₂(PH₃)₂]（4b）以中等收率分离得到。
该类化合物的另一种合成路径为直接光解配合物[(CO)₃M(PH₃)₃]（M = Cr（5a）、M = W（5b））。通过磷-31（³¹P）核磁共振光谱、红外光谱以及X射线晶体结构分析对产物进行了全面表征。
此外，本研究还证实了2a可作为单源前驱体，用于合成化学计量比可控的磷化铬（CrP）纳米颗粒。