Formula C6H11O3P Appearance white waxy solid | Molar mass 162.12 g/mol | |
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Trimethylolpropane phosphite, C2H5C(CH2O)3P, is a phosphite ester used as a ligand in organometallic chemistry. Trimethylolpropane phosphite is sometimes abbreviated to EtCage. It is a white solid that is soluble in organic solvents.
Ligand in coordination chemistry
It is prepared by reaction of trimethylolpropane with phosphorus trichloride or by transesterification with trimethylphosphite:
P(OMe)3 + EtC(CH2OH)3 → 3 MeOH + EtC(CH2O)3PThe first member of this series was derived from trimethylolethane, but these derivatives are often poorly soluble. For this reason, the ethyl derivative has received more attention.
Several EtCage complexes are known, since the ligand is highly basic (for a phosphite) and has a small ligand cone angle (101°). Illustrative complexes include [(EtCage)2Mo(CO)4], [Ir4(CO)11(EtCage)] and (CpMe5)RuCl(EtCage)2, shown below.