| Abstract: | Treatment of titanyl sulfate in about 60 mM sulfuric acid with NaLOEt (LOEt?=(η5‐C5H5)Co{P(O)(OEt)2}3]?) afforded the μ‐sulfato complex (LOEtTi)2(μ‐O)2(μ‐SO4)] ( 2 ). In more concentrated sulfuric acid (>1 M ), the same reaction yielded the di‐μ‐sulfato complex (LOEtTi)2(μ‐O)(μ‐SO4)2] ( 3 ). Reaction of 2 with HOTf (OTf=triflate, CF3SO3) gave the tris(triflato) complex LOEtTi(OTf)3] ( 4 ), whereas treatment of 2 with Ag(OTf) in CH2Cl2 afforded the sulfato‐capped trinuclear complex {(LOEt)3Ti3(μ‐O)3}(μ3‐SO4){Ag(OTf)}]OTf] ( 5 ), in which the Ag(OTf) moiety binds to a μ‐oxo group in the Ti3(μ‐O)3 core. Reaction of 2 in H2O with Ba(NO3)2 afforded the tetranuclear complex (LOEt)4Ti4(μ‐O)6 ( 6 ). Treatment of 2 with {Rh(cod)Cl}2] (cod=1,5‐cyclooctadiene), Re(CO)5Cl], and Ru(tBu2bpy)(PPh3)2Cl2] (tBu2bpy=4,4′‐di‐tert‐butyl‐2,2′‐dipyridyl) in the presence of Ag(OTf) afforded the heterometallic complexes (LOEt)2Ti2(O)2(SO4){Rh(cod)}2]OTf]2 ( 7 ), (LOEt)2Ti(O)2(SO4){Re(CO)3}]OTf] ( 8 ), and {(LOEt)2Ti2(μ‐O)}(μ3‐SO4)(μ‐O)2{Ru(PPh3)(tBu2bpy)}]OTf]2 ( 9 ), respectively. Complex 9 is paramagnetic with a measured magnetic moment of about 2.4 μB. Treatment of zirconyl nitrate with NaLOEt in 3.5 M sulfuric acid afforded (LOEt)2Zr(NO3)]LOEtZr(SO4)(NO3)] ( 10 ). Reaction of ZrCl4 in 1.8 M sulfuric acid with NaLOEt in the presence Na2SO4 gave the μ‐sulfato‐bridged complex LOEtZr(SO4)(H2O)]2(μ‐SO4) ( 11 ). Treatment of 11 with triflic acid afforded (LOEt)2Zr]OTf]2 ( 12 ), whereas reaction of 11 with Ag(OTf) afforded a mixture of 12 and trinuclear {LOEtZr(SO4)(H2O)}3(μ3‐SO4)]OTf] ( 13 ). The ZrIV triflato complex LOEtZr(OTf)3] ( 14 ) was prepared by reaction of LOEtZrF3 with Me3SiOTf. Complexes 4 and 14 can catalyze the Diels–Alder reaction of 1,3‐cyclohexadiene with acrolein in good selectivity. Complexes 2 – 5 , 9 – 11 , and 13 have been characterized by X‐ray crystallography. |
