[2,6-Bis(diphenylphosphinooxy)phenyl]bis(trimethylphosphine)cobalt(I)

Abstract

The title compound, [Co(C30H23O2P2)(C3H9P)2], was synthesized by the addition of a Co(PMe3)4 solution to (PPh2O)2C6H4. The CoI atom displays a trigonal-bipyramidal geometry with the two P atoms of the ‘PCP’ pincer ligand and the P atom of one of the trimethyl phosphine ligands forming the basal plane, whereas the metalated C atom and the P atom of the second phospine ligand occupy the apical sites. The Co—C distance is 1.961 (2) Å and the C—Co—P angle is 171.96 (6)°.

Silane Activation with Cobalt on the POCOP Pincer Ligand Platform

“…Inspired by the work of Li and Sun, , we first attempted to use Co­(PMe 3 ) 4 and MeCo­(PMe 3 ) 4 to activate POCOP pincer ligands bearing isopropyl groups as the phosphorus substituents. Treatment of 1,3-( i Pr 2 PO) 2 C 6 H 4 with Co­(PMe 3 ) 4 failed to produce any pincer complexes.…”

“…The very first example was reported in 2009 by Li and co-workers, who used MeCo­(PMe 3 ) 4 to activate the central C–H bond of Ph 2 PO­(CH 2 ) 3 OPPh 2 , resulting in the formation of {κ P ,κ C ,κ P -(Ph 2 PO) 2 C 3 H 5 }­Co­(PMe 3 ) 2 . This strategy has been extended to the synthesis of other cobalt POCOP pincer complexes, although the phosphorus substituents are limited to phenyl groups . The tert -butyl derivatives can be accessed from {κ P ,κ C ,κ P -2,6-( t Bu 2 PO) 2 C 6 H 3 }­CoI, which is available via lithiation of 1,3-( t Bu 2 PO) 2 -2-I-C 6 H 3 , followed by the addition of CoI 2 ·THF .…”

Cobalt POCOP Pincer Complexes via Ligand C–H Bond Activation with Co2(CO)8: Catalytic Activity for Hydrosilylation of Aldehydes in an Open vs a Closed System

“…6c,20 Thus, we were more intrigued by the method developed by Li and co-workers, who successfully activated the pincer central C−H bonds with MeCo(PMe 3 ) 4 (eqs 2 and 3) 21, 22 or Co(PMe 3 ) 4 (eq 4). 23 The above procedures prompted us to examine if the C−H bond activation protocol could be broadly applied to other POCOP pincer systems. Our attempts to synthesize {2,6-( i Pr 2 PO) 2 C 6 H 3 }Co(PMe 3 ) 2 under similar conditions were, however, unsuccessful.…”

“…In our experience with POCOP pincer complexes, the P–O bonds are vulnerable to attack by nucleophiles or bases, especially when the phosphorus substituents are smaller than tert -butyl groups (e.g., isopropyl and cyclopentyl groups). , Thus, we were more intrigued by the method developed by Li and co-workers, who successfully activated the pincer central C–H bonds with MeCo­(PMe 3 ) 4 (eqs and 3) , or Co­(PMe 3 ) 4 (eq 4 ). The above procedures prompted us to examine if the C–H bond activation protocol could be broadly applied to other POCOP pincer systems. Our attempts to synthesize {2,6-( i Pr 2 PO) 2 C 6 H 3 }­Co­(PMe 3 ) 2 under similar conditions were, however, unsuccessful.…”

Synthesis, characterization and reactivity of iron- and cobalt-pincer complexes

“…[18][19][20][21][22][23][24][25][26] It should be noted that several related iron and cobalt complexes containing anionic pincer-type PCP, POCOP, and PN pyrrole P frameworks have been described. [27][28][29][30][31][32][33] In this report, the synthesis, characterization, and reactivity of new (PONOP)M (M = Fe and Co) complexes are examined. Reactions of these metal PONOP complexes with NaBEt 3 H result in catalytically competent systems for the hydrosilylation of carbonyl groups.…”