Trapping Tetramethoxyzincate and -cobaltate(II) between Mo<sub>2</sub><sup>4+</sup> Units CottonF. Albert LiuChun Y. MurilloCarlos A. WangXiaoping 2003 Two compounds of a new type, [Mo<sub>2</sub>](CH<sub>3</sub>O)<sub>2</sub>M(CH<sub>3</sub>O)<sub>2</sub>[Mo<sub>2</sub>] where [Mo<sub>2</sub>] is an abbreviation for Mo<sub>2</sub>[(<i>p</i>-MeOC<sub>6</sub>H<sub>4</sub>)NCHN(<i>p</i>-MeOC<sub>6</sub>H<sub>4</sub>)]<sub>3</sub> and M = Zn (<b>1</b>) and Co (<b>2</b>), are reported. Discrete [M(OR)<sub>4</sub>]<sup>2-</sup> ions, either as such or in the μ<sub>2</sub>,η<sup>4</sup> role, have not heretofore been described. In these compounds they have distorted tetrahedral structures and bridge two [Mo<sub>2</sub>] groups in much the same way as did SO<sub>4</sub><sup>2-</sup>, MoO<sub>4</sub><sup>2-</sup>, and WO<sub>4</sub><sup>2-</sup> ions in other recently reported compounds (Cotton, F. A.; Donahue, J. P.; Murillo, C. A. <i>Inorg. Chem. </i><b>2001</b>, <i>40</i>, 2229). The <sup>1</sup>H NMR spectrum of <b>1</b> and the visible spectrum and magnetic properties of <b>2</b> are consistent with these structures. The M(OCH<sub>3</sub>)<sub>4</sub> bridges are moderately effective in coupling the two [Mo<sub>2</sub>] redox centers. Compounds <b>1</b> and <b>2</b> may also be viewed as having Zn<sup>II</sup> and Co<sup>II</sup> centers tetrahedrally coordinated by the bidentate ligand [Mo<sub>2</sub>[(<i>p</i>-MeOC<sub>6</sub>H<sub>4</sub>)NCHN(<i>p</i>-MeOC<sub>6</sub>H<sub>4</sub>)]<sub>3</sub>(OMe)<sub>2</sub>]<sup>-</sup>. From that point of view they may be compared with Zn(DPM)<sub>2</sub> and Co(DPM)<sub>2</sub> (<b>3</b>), where DPM is the anion of dipivaloylmethane. For purposes of comparison, <b>3</b> has been fully characterized structurally, spectroscopically, and magnetically. Close analogies between <b>2</b> and <b>3</b> are shown to exist.