TY - JOUR
T1 - Uranium(IV) bis(amido), imido and bis(acetylide) complexes
T2 - Synthesis, molecular structure, solution dynamics and interconversion reactions
AU - Straub, Thomas
AU - Frank, Walter
AU - Reiss, Guido J.
AU - Eisen, Moris S.
PY - 1996/6/21
Y1 - 1996/6/21
N2 - Reactions of [UMe2(C5Me5)2] with primary aromatic or aliphatic amines led to the rapid formation of monomeric uranium(IV) complexes [U(C5Me5)2(NHR)2] (R = 2,6-dimethylphenyl 1, Et 2 or But 3). The compounds were characterized by standard techniques and for 1, by X-ray diffraction. In co-ordinating solvents like tetrahydrofuran (thf) compound 1 reacted intramolecularly releasing one primary amine and forming the imidouranium(IV) [U(C5Me5)2{N(C6H3Me 2-2,6)}]·thf 4, whereas in non-co-ordinating solvents the base-free [U(C5Me5)2{N(C6H3Me 2-2,6)}] 5 was obtained. The thf in 4 was found not to be in equilibrium with bulk solvents, and different proton chemical shifts for the adducted base were observed as a function of temperature following a Curie-Weiss behaviour. σ-Bond metathesis reactions of the bis(amido) and/or imido complexes with terminal alkynes produced the bis(acetylide) complexes [U(C5Me5)2(C≡CR)2] (R = Ph 6 or But 7) active species for the regioselective oligomerization of terminal alkynes, which can be prepared also from the reaction of [UMe2(C5Me5)2] with 2 equivalents of the corresponding terminal alkyne. Reactivity studies show the possible interconversion among these bis(amido), imido and bis(acetylide) complexes.
AB - Reactions of [UMe2(C5Me5)2] with primary aromatic or aliphatic amines led to the rapid formation of monomeric uranium(IV) complexes [U(C5Me5)2(NHR)2] (R = 2,6-dimethylphenyl 1, Et 2 or But 3). The compounds were characterized by standard techniques and for 1, by X-ray diffraction. In co-ordinating solvents like tetrahydrofuran (thf) compound 1 reacted intramolecularly releasing one primary amine and forming the imidouranium(IV) [U(C5Me5)2{N(C6H3Me 2-2,6)}]·thf 4, whereas in non-co-ordinating solvents the base-free [U(C5Me5)2{N(C6H3Me 2-2,6)}] 5 was obtained. The thf in 4 was found not to be in equilibrium with bulk solvents, and different proton chemical shifts for the adducted base were observed as a function of temperature following a Curie-Weiss behaviour. σ-Bond metathesis reactions of the bis(amido) and/or imido complexes with terminal alkynes produced the bis(acetylide) complexes [U(C5Me5)2(C≡CR)2] (R = Ph 6 or But 7) active species for the regioselective oligomerization of terminal alkynes, which can be prepared also from the reaction of [UMe2(C5Me5)2] with 2 equivalents of the corresponding terminal alkyne. Reactivity studies show the possible interconversion among these bis(amido), imido and bis(acetylide) complexes.
UR - http://www.scopus.com/inward/record.url?scp=33749100725&partnerID=8YFLogxK
U2 - 10.1039/dt9960002541
DO - 10.1039/dt9960002541
M3 - 文章
AN - SCOPUS:33749100725
SN - 0300-9246
SP - 2541
EP - 2546
JO - Journal of the Chemical Society. Dalton Transactions
JF - Journal of the Chemical Society. Dalton Transactions
IS - 12
ER -