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Some metal organic frameworks (MOFs) incorporate nodes that are nanoscale metal oxides, and the hydroxy-containing functional groups on them provide opportunities for introducing catalytic sites with precisely defined structures. Investigations have been done to understand the structures of these groups on nodes and node vacancies, because, in prospect, atomic-scale modulation of the composition, areal density, and/or siting of the groups would open up possibilities for exquisite tuning of the siting and performance of subsequently anchored catalytic units (e.g., single metal ions, pairs of metal ions, or well-defined metal-ion-containing clusters). We have combined infrared (IR) spectroscopy and density functional theory (DFT) to demonstrate tuning of these sites, namely, hydrogen-bonded OH/OH2 groups on the Zr6 nodes of the MOFs UiO-66 and NU-1000 via the intermediacy of node methoxy (or ethoxy) groups formed from methanol (or ethanol). Methoxy (or ethoxy) groups on node vacancy sites are converted to a structure incorporating one vacant Zr site and one terminal OH group per face by reaction with water. Our results highlight how the combination of DFT and IR spectroscopy facilitates the determination of the identity and chemistry of the functional groups on MOF node vacancies and defect sites.

Metal-organic frameworks with Zr6 nodes, UiO-66 and NU-1000, were investigated as supports for Ir(CO)2 and Ir(C2H4)2 complexes. A single bonding site for the iridium is identified on the nodes of NU-1000, whereas two sites are identified on UiO-66, although at low iridium loadings only one site is occupied. Density functional theory calculations provide structural results that are in good agreement with infrared and X-ray absorption fine-structure spectra. The reactivity of node-supported Ir(CO)2 with C2H4 and the catalytic activity and selectivity of the species initially present as Ir(C2H4)2 for ethylene hydrogenation and dimerization were investigated both experimentally and computationally and shown to be strongly influenced by the node.

A series of six neutral, tetrametallic, molecular rectangles are synthesized that have the form ([Re(CO)3]2BiBzlm)2-Mu,Mu'-(LL)2, where BiBzlm is 2,2'-bisbenzimidazolate and LL is reducible, dipyridyl or diazine ligand. The X-ray crystallography and computational modeling shows that the observed differences largely reflect detailed geometric configurational differences that can either facilitate or frustrate productive direct orbital overlap.

A real-time deoxyribonucleic acid (DNA) detection method that uses single-strand DNA (ssDNA)-modified nanoparticle probes and micropatterned chemoresponsive diffraction gratings interrogated simultaneously at multiple laser wavelengths is presented. Significant signal amplification is observed due to the use of nanoparticle probe, which is heavily functionalized with ssDNA complementary to target DNA.

Micropatterning of the vaporchromic charge-transfer salt, [Pt-(CNC6H4C10H21)(sub 4)][Pd(CN)(sub 4)], on transparent platforms yields such structures that behave as transmissive chemoresponsive two-dimensional visible-region diffraction grating or photonic lattices. These lattices are investigated as volatile organic compound (VOC) sensors via a newly devised signal transduction scheme involving diffraction of visible light.

A computational approach for estimating thermal electron-transfer reaction distances in symmetrical mixed-valence compounds is presented. It is concluded that electronic delocalization effects can prompt effective one-electron-transfer distances to differ from simple geometric separation distances.

A putative octupolar super chromophore Ru(trans-4,4'-diethylaminostyryl-2,2'-bipyridine)(sub 3)(super 2+) has been analyzed using the polarized hyper-Rayleigh scattering technique. It was found that the symmetry of the excited state, and therefore the hyperpolarizability tensor, is dipolar in nature, as shown by electroabsorption or electronic Stark effect experiments. These results indicate that changes in dipole moment correlate with optical excitation.

Thin-film forms of molecular materials composed of selected tetrarhenium square assemblies were prepared and identified. It was believed that the films were intensely attached and characterized by few pinhole defects. Results of the electrochemical transport experiments revealed that the materials were porous in terms of small solution-phase permeants although hindering larger permeants. Also, a single isomer crystal structure was discovered in one of the square assemblies.

Sol-gel-encapsulation technology of fragile molecules and biomolecules such as enzymes/coenzymes in clear, porous silicate matrices has been successfully demonstrated. The inherent alcohol-plus-aldehyde dual response capacity of the silicate-encapsulated yeast alcohol dehydrogenase enzyme/cofactor combination to transform irreversible probes into reusable chemical sensors is investigated. The results are discussed.

The spin-orbit induced splitting of the visible-region intervalence transition was observed to study the orbital specificity of the charge transfer process. Raman and electronic effect spectroscopies were used investigate the resonance of the component transitions. Measured orbital-specific electron-transfer distances, coupling energies and reorganization energy were shown to be dependent on orbital identity.

The reaction of trans-dioxorhenium complex with methyl trifluoromethanesulfonate produces high-valent, highly stable oxo-, methoxorhenium complexes. These complexes are identical to analogous oxo, hydroxo complexes of trans-dioxorhenium(V)tetrapyridyl species, which is a model system for interfacial two-electron, two proton transfer reaction sequences. High pH stabilizes the rhenium(IV) state for several complexes with respect to redox disproportionation.

Fabrication of a ZIF-8 thin film-based Fabry-Perot device as a selective sensor for chemical vapors and gases is reported. The newly prepared ZIF-8 thin film and a series of ZIF-8 thin films of various thicknesses grown on silicon substrates are also reported.

Nickel bis(dicarbollide) is used as a fast, one-electron outer sphere redox couple in dye-sensitized solar cells and device performances with this anionic shuttle are examined. Open-circuit voltage decay is used for probing the kinetics of the Ni(III)/(IV) bis(dicarbollide) redox couple and electron interception is slower than ferrocene/ferrocenium, which has described the large discrepancy in open-circuit voltage potentials between these two redox shuttles.

The article presents a new approach, which employs the process of rational designing of the various organic building blocks for controlling the catenation of the metal-organic frameworks (MOFs). The synthesis and the applications of these MOFs are also discussed.

Click chemistry is used for constructing a postsynhetically modified noncatenated, Zn-based metal-organic framework (MOF) material bearing silyl-protected acetylenes. A solvent-based, selective deprotection strategy is used for clicking two different organic azides onto the MOF crystals, which have resulted in a porous material whose internal and external surfaces are differently functionalized.

Titanium dioxide based dye-sensitized solar cells are prepared that have incorporated corrosion-protected silver nanoparticles as plasmonic optical elements of the photoelectrode. The optical enhancements have translated into photocurrent enhancements, with the thinnest Ti[O.sub.2] coatings showing 9-fold current enhancements under optimal monochromatic illumination.

The tetratopic ligand 1,2,4,5-tetrakis(4-carboxyphenyl)benzene is used as a key building block for preparing a permanently microporous metal-organic framework with Lewis acidic (porphyrin)Zn struts (ZnPO-MOF). ZnPO-MOF has efficiently catalyzed acyl-transfer reactions by preconcentrating the substrates within its pores.

A new noncatenated metal-organic framework containing pendant alcohol functionalities is prepared and the alcohols are post-synthetically converted to either lithium or magnesium alkoxides. The incorporated metal ions have induced an unusual pattern of binding energetics for [H.sub.2]:isosteric heats of adsorption increase, rather than decrease, with increasing [H.sub.2] loading.

The utility of the self-sorting strategy for the spontaneous assembly of highly ordered, rigid supramolecular boxes possessing catalytic properties is described. The catalytically active boxes have affected both size-selective and enantioselevtive oxidation catalysis.

The synthesis of narrowly dispersed porphyrin nanowires whose length is finely tuned by using an amphiphilic polymer surfactant, Pluronic F127, is described. The polymer-assisted hierarchical assembly strategy is used for the preparation of other multifunctional materials from molecular building blocks and is used for examining these materials in applications concerning catalysis, separation, storage, and energy transfer.

Rapid separation of mixtures of metal-oxide framework materials (MOFs) is achieved via a solvent-based density-discrimination method. The prerequisites for the method are density differences between product and impurities and availability of an appropriate solvent.

The synthesis and photophysical properties of butadiyne-linked chlorophyll and porphyrin dimers in toluene solution and in several self-assembled prismatic structures are described. The self-assembly of discrete macrocyclic prisms provides a new method for controlling singlet exciton flow in antenna systems for artificial photosynthesis and solar cell applications.