Pentaerythritol and dipentaerythritol phosphites: Metal-organic network-forming ligands

Megan Dellinger
College of William and Mary

The bicyclic (caged) phosphite esters P(OCH2)3CH2OH and (P(OCH2)3CCH2)2O were synthesized via transesterification of P(OPh)3 with pentaerythritol and dipentaerythritol, respectively. Further esterification of P(OCH2)3CH2OH with acid chlorides in the presence of a base yielded esters of the type, P(OCH2)3CCH2O2CR (R = Ph, 4-tBuC6H4, 4-O2NC6H4, 3-pyridyl, 4-pyridyl, ?? p-C6H4, ?? m-C6H4, 1/3 1,3,5-C6H3). Because of their small cone angles and high p-acidity, the bridging (P(OCH2)3CCH2)2O and P(OCH2)3CCH2O2CR ligands are of interest for formation of potentially catalytically useful networks of low valent metals. Therefore, insoluble, self-assembling metal-phosphite complexes of Cu(I) halides and of Ni(0) were prepared. X-ray crystal structures of P(OCH2)3CCH2O2C-4-pyridyl, [CuBr((P(OCH2)3CCH2)2O)]8??MeCN, and {[(?5-MeCp)Mn(CO)2]2(??-(P(OCH2)3CCH2)2O)} are presented.