The Syntheses Of Metallomacrocycles Containing Unsymmetrical Bridging Ligands And The Crystal Structures Of Dl-[Mo{Hb(3,5-Me2c3hn2)(3)}(No)(Oc6h4ch2ch2o-4)](2)Center Dot 2ch(2)Cl(2) And Dl-[W{Hb(3,5-Me2c3hn2)(3)}(No)(Oc6h3no2-4-Ch2ch2o-3)](2)Center Dot Ch2cl2

Metallomacrocycles containing {M(NO)(Tp(Me2))} [Tp(Me2)=HB(3,5-Me2C3HN2)(3); M=Mo or W] have been synthesized by direct reaction between [M(NO)(Tp(Me2))I-2] and a heterotopic ligand HE-E'H {1,x-HOC6H4XOH (x=3, X=CO; x=3 or 4, X=CH2 or CH2CH2)} in the presence of NEt3. Only DL and meso isomers were isolated from the reactions where M=Mo, x=4 and X=CO or CH2CH2 but both DL and meso and syn and anti isomers from the other reaction mixtures. Stereo-controlled synthetic routes to syn and anti isomers containing the OC6H4CH2O-3 bridging ligand were developed through formation of [M(NO)(Tp(Me2))(OC6H4CHO-3)](2) (M=Mo or W) followed by reduction to [M(NO)(Tp(Me2))(OC6H4CH2OH-3)](2) and subsequent reaction with [M'(NO)(Tp(Me2))I-2] (M'=W or Mo) to give [{M(NO)(Tp(Me2))}(mu -OC6H4CH2O-3)(2){M'(NO)(Tp(Me2))}]. The trinuclear complex [{Mo(Tp(Me2))(NO)}(mu -OC6H4CH2O-3)(2){W(Tp(Me2))(NO)}(2)(mu -1,3-OC6H4O)] was obtained from the reaction of [Mo(NO)(Tp(Me2))(OC6H4CH2OH-3)](2) with the binuclear complex [{W(NO)(Tp(Me2))I}(2)(mu -1,3-O2C6H4)]. The crystal structures of DL-[Mo(Tp(Me2))(NO)(OC6H4CH2CH2O-4)](2) and [W(Tp(Me2))(NO)(OC6H3NO2-4-CH2CH2O-3)](2) were established.