We have synthesized [Pt(CN-iso-C 3 H 7 ) 4 ][M(CN) 4 ] (M ) Pt, Pd) and studied their reversible hydration and sorption properties with UV-vis, FT-IR spectroscopy, and X-ray diffraction. Powder diffraction studies show that anhydrous [Pt(CN-iso-C 3 H 7 ) 4 ][Pt(CN) 4 ] and [Pt(CN-iso-C 3 H 7 ) 4 ][Pd(CN) 4 ] crystallize in a tetragonal space group with nearly identical lattice constants. Gravimetric studies reveal that variable guest-host stoichiometries occur when solid [Pt(CN-iso-C 3 H 7 ) 4 ][Pt(CN) 4 ] sorbs the guest at room temperature from the gas phase [water, 12.1(1) molecules per formula unit, chloroform 6.0(1), methanol 8.0(1), and trifluoroethanol 4.1(1)]; these sorption processes are reversible. The unit cell distances in the tetragonal ab-plane expand dramatically when the solvent guests are sorbed, but changes along the c-axis (the M-M direction) are minimal. Crystallization of [Pt(CN-iso-C 3 H 7 ) 4 ][Pt(CN) 4 ] from water gives monoclinic crystals of a hexadecahydrate [Pt(CN-iso-C 3 H 7 ) 4 ][Pt(CN) 4 ]‚16H 2 O. This salt consists of alternating cation/anion chains along b with an average Pt-Pt distance of b/2 ) 3.1521(1) Å. The sixteen water molecules per formula weight interlace neighboring chains via H-bonding with each other and the CNions of the Pt(CN) 4 2units. The shifts in the UV-vis and IR spectra that occur when solvent guests are sorbed by the double complex salts are discussed in terms of the lattice expansions that are observed. A mechanism for the lattice expansions that accompany the sorption of guest molecules is proposed.

We have studied the sorption of volatile organic compounds (VOCs) by [(n-C 4 H 9 ) 4 N] 2 [Pt-(CN) 4 ] and [Pt(p-CN-C 6 H 4 -C 10 H 21 ) 4 ][Pt(CN) 4 ] with FTIR spectroscopy. The data indicate a strong correlation exists between ν(CN) stretching frequencies in the [Pt(CN) 4 ] 2ions and the hydrogen bonding ability of the VOC (as expressed by Abraham's R values). The ν(CN) stretching frequencies for each salt with sorbed VOC indicate that similar VOC-material interactions are present in both. The correlation of the IR data for [Pt(p-CN-C 6 H 4 -C 10 H 21 ) 4 ]-[Pt(CN) 4 ] with the previously reported NIR data was only successful for solvents with R > 0.15. These results suggest that vapochromic shifts in the electronic transitions of [Pt(p-CN-C 6 H 4 -C 10 H 21 ) 4 ][Pt(CN) 4 ] result not only from H-bonds between the VOC and [Pt(CN) 4 ] 2but also from one or more additional mechanisms that are most important for solvents with low H-bond donor character (R < 0.15).

A convenient synthesis of tris-heteroleptic polypyridyl [Ru(pp)(pp‘)(pp‘ ‘)]2+ complexes is reported (where pp, pp‘, and pp‘ ‘ represent three different polypyridyl ligands). Photolysis of [BzRu(pp)Cl]Cl (Bz = η6-C6H6) gives a mixture of Ru(pp)(CH3CN)2Cl2 and [Ru(pp)(CH3CN)3Cl]Cl. Refluxing this mixture with pp‘ yields Ru(pp)(pp‘)Cl2. Finally, refluxing Ru(pp)(pp‘)Cl2 with pp‘ ‘ in a 75% ethanol/water solution gives [Ru(pp)(pp‘)(pp‘ ‘)]2+. No ligand scrambling is observed. The complexes are characterized by 1H NMR, elemental analysis, FAB-MB, UV−vis and emission spectroscopy, and cyclic voltammetry.

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