NEUTRAL GUEST CAPTURE VIA LEWIS ACID BASE MOLECULAR SQUARE RECEPTORS - X-RAY CRYSTAL-STRUCTURE OF S-(PET3)(2)PT)]AG-2)(+6)(PHENAZINE)-(-OSO2CF3)(6)/

Interaction of ynylpyridyl)(2))(cis-(L)M)]Ag-2}(+6)(-OSO2CF3)(6), wher e M = Pt(II) or Pd(II) and L = dppp or 2PEt(3), with pyridine, pyrazin e, phenazine, or 4,4'-dipyridyl ketone results in coordination Lewis a cid/base host-guest assemblies via the ''pi-tweezer effect'' and mono or bis neutral guest coordination. All host-guest complexes are air st able microcrystalline solids with decomposition points greater than 17 0 degrees C. The homometallic Pt(II) receptors are more stable than th e heteroaromatic Pt(II)-Pd(II) receptors toward heteratom-containing a romatic guests. The X-ray crystal structure of the host-guest complex cis-(PEt3)(2)Pt)]Ag-2}(+6)(phenazine)(-OSO2CF3)(6) is reported. The cr ystals with the empirical formula C62H68AgF9N3O9P4Pt2S3 are triclinic P (1) over bar with a = 12.3919(8) Angstrom, b = 17.160(1) Angstrom, c = 18.932(1) Angstrom, alpha = 90.892(1)degrees, beta = 97.127(1)degre es, gamma = 89.969(1)degrees, and Z = 2.