Syntheses and Structures of Thorium(IV) Complexes with Bis(diphenylphosphino)ethane dioxide, Ph2P(O)CH2CH2P(O)Ph2, and Bis-(diphenylphosphoryl)amide, [Ph2P(O)NP(O)Ph2]-

Dedicated to Prof. Hans Hartl on the occassion of his 60th birthday

The cationic thorium(IV) complexes [Th{Ph2P(O)CH2CH2P(O)Ph2}2(NO3)3]NO3 and [Th{Ph2P(O)NP(O)Ph2}3(dmso)2]NO3 have been synthesized by reactions of Th(NO3)4 · 5H2O with bis(diphenylphosphino)ethane dioxide, Ph2P(O)CH2CH2P(O)Ph2 (L1), or ammonium bis-(diphenylphosphoryl)amide, (NH4)[Ph2P(O)NP(O)Ph2] (NH4L2), and subsequent recrystallization from dimethyl sulfoxide. The products have been studied spectroscopically and by X-ray crystallography.
The thorium atom is ten-co-ordinate in the [Th(L1)2(NO3)3]+ cation with a co-ordination sphere which does not meet one of the idealized polyhedra for ten-co-ordination. Th-O bonds have been found in the range between 2.342(3) (phosphine oxide) and 2.599(4) Å (nitrate).
An eight-co-ordinate thorium atom is found in the [Th(L2)3(dmso)2]+ cation. The almost ideal square-antiprismatic environment of the metal is occupied by oxygen atoms with Th-O bond lengths between 2.363(6) and 2.392(11) Å.