A New Class of Bis(μ-aryloxy)-Bridged Dimers with First-Row Divalent Transition-Metal Ions. Synthesis and Structural Characterization of the (Et4N)2(M2Cl4(O-C6H4-p-CH3)2) Complexes (M: Mn(II), Fe(II), Co(II), Zn(II), and Cd(II)).