201468-13-5Relevant academic research and scientific papers
Ring functionalized cyclopentadienyl derivatives of niobium and tantalum: Molecular structures of (η5-C5H4-CO2CH3) M(CO)4 where M = Nb and Ta and (η5-C5H4-CO2CH2C6H5)Nb(CO)4
Bitterwolf, Thomas E.,Gallagher, Skip,Rheingold, Arnold L.,Yap, Glenn P.A.
, p. 27 - 33 (2007/10/03)
Reaction of Na[M2(μ-Cl)3(CO)8], where M = Nb or Ta, with NaC5H4R, where R = COCH3, CO2CH3, CO2C2H5, COC6H5, COCH2C6H5, LiC5H4C(CH3)CH2, or NaC9H7 gives the corresponding (η5-C5H4R)M(CO)4, or (η5-C9H7)M(CO)4 compounds in good yield. NaC5H4COCH2C6H5, a new cyclopentadienyl synthon, was used to prepare TlC5H4COCH2C6H5, and (η5-C5H4COCH2C6H5)Mn(CO)3. The latter was fully characterized as a model compound for the new ligand. The niobium and tantalum compounds are air-stable as solids but readily undergo oxidation in solution. Compounds were characterized by IR, 1H and 13CNMR spectroscopies, and elemental analyses. Molecular structures of three compounds were determined. (η5-C5H4CO2CH3)Nb(CO)4: monoclinic, P21/c, a = 12.664(6) A, b = 6,390(3) A, c,= 15.355(9) A, β = 97.81(4)°, V= 1231(1) A3, Z = 4, and A(F) = 3.90%. (η5-C5H4CO2CH3)Ta(CO)4: monoclinic, P21/c, a = 12.612(4) A, b = 6.399(1) A, c, = 15.273(6) A, β = 97.89(3)°, V= 1220.9(4) A3, Z = 4, and R(F) = 5.67%. (η5-C9H7)Nb(CO)4: monoclinic, P21/c, a = 16.353(2) A, b = 7.959(1) A, c, = 12.778(4) A, β = 106.14(2)°, V= 1597.7(6) A3, Z = 4, and R(F) = 2.48%.
