Zusammenfassung
The reaction of the phosphinidene complex [Cp*P{W(CO)(5)}(2)] (1a) (Cp*=C5Me5) with the anionic cyclo-Pn ligand complex [(eta(3)-P-3)Nb(ODipp)(3)](-) (2, Dipp = 2,6-diisopropylphenyl) resulted in the formation of [{W(CO)(5)}(2){mu(3),eta(3:1:1)-P4Cp*}Nb(ODipp)(3)](-) (3), which represents an unprecedented example of a ring expansion of a polyphosphorus-ligand complex initiated by a phosphinidene ...
Zusammenfassung
The reaction of the phosphinidene complex [Cp*P{W(CO)(5)}(2)] (1a) (Cp*=C5Me5) with the anionic cyclo-Pn ligand complex [(eta(3)-P-3)Nb(ODipp)(3)](-) (2, Dipp = 2,6-diisopropylphenyl) resulted in the formation of [{W(CO)(5)}(2){mu(3),eta(3:1:1)-P4Cp*}Nb(ODipp)(3)](-) (3), which represents an unprecedented example of a ring expansion of a polyphosphorus-ligand complex initiated by a phosphinidene complex. Furthermore, the reaction of the pnictinidene complexes [Cp*E{W(CO)(5)}(2)] (E= P: 1a, As: 1b) with the neutral complex [Cp ''' Co(eta(4)-P-4)] (Cp ''' = 1,2,4-tBu(3)C(5)H(2)) led to a cyclo-P4E ring (E= P, As) through the insertion of the pentel atom into the cyclo-P4 ligand. Starting from 1a, the two isomers [Cp ''' Co(mu(3),eta(4:1:1)-P5Cp*){W(CO)(5)}(2)] (5a, b), and from 1b, the three isomers [Cp ''' Co(mu(3), eta(4:1:1)-As-P4Cp*){W(CO)(5)}(2)] (6a-c) with unprecedented cyclo-P4E ligands (E=P, As) were isolated. The complexes 6a-c represent unique examples of ring expansions which lead to new mixed five-membered cyclo-P4As ligands. The possible reaction pathways for the formation of 5a, b and 6a-c were investigated by a combination of temperature-dependent P-31{H-1} NMR studies and DFT calculations.