Reactivity of Trimetallic Organoyttrium Hydride Complexes. Synthesis of the Alkoxy Hydride Anions x3-x(μ3-H)>- (x = 0-2) Including the X-ray Crystal Structure of 3(μ3-H)>22

Article abstract of DOI:10.1021/ja00210a021

<<(C5H5)2Y(μ-H)>3(μ₃-H)> (1) reacts with 1 equiv of CH3OH at 0 deg C to form <<(C5H5)2Y(μ-OCH3)><(C5H5)2Y(μ-H)>2Y(μ₃-H)> (2).Reaction of 1 with 2 equiv of CH3OH or 2 with 1 equiv CH3OH at 0 deg C forms <<(C5H5)2Y(μ-OCH3)>2<(C5H5)2Y(μ-)H>(μ₃-H)> (3). <<(C5H5)2Y(μ-OCH3)>3(μ₃-H)> (4) can be formed from 1-3 with the appropiate amount of CH3OH at 0 deg C.The central μ₃-H of these trimers does not react with CH3OH.All trimetallic species were identified by elemental analysis, hydrolytic decomposition and 1H NMR spectroscopy.Crystallization of 4 from THF gives <<(C5H5)2Y(μ-OCH3)>3(μ₃-H)>22 (5) in space group P2₁/n with the following unit cell dimensions: a = 20.852 (9), b = 13.984 (5), c = 31.590 (9) Angstroem; β = 92.48 (4) deg; V = 9203 (7) Angstroem³, Z = 8; D_calcd = 1.81 g cm^-3.Least-squares refinement on the basis of 2987 observed reflections led to a final R value of 0.080.The structure contains an anionic <(C5H5)2Y(μ-OCH3)>3(μ₃-H)^- unit, which has a triangular arrangement of three (C5H5)2Y units bridged by methoxide groups.The central hydride ligand was not located but was observable by 1H NMR spectroscopy.The cation in 5 is comprised of a trimetallic anion like that just described, to which are attached two (THF)3Li groups, i.e., <<(THF)3Li(μ-η¹,η⁵-C5H5)(C5H5)Y(μ-OCH3)>2<(C5H5)2Y(μ-OCH3)>(μ₃-H)>⁺.The (THF)3Li units bind on the same side of the trimetallic plane to carbon atoms in two different C5H5 rings with Li-C distances of 2.50 (8)-2.67 (5) Angstroem.The two trimetallic parts are otherwise similar, with average Y-O(OCH3) and Y-C(C5H5) distances of 2.28 (2) and 2.73 (2) Angstroem.