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Three-dimensional m * n arrays of metal ion clusters, assembled as aromatic stacks of planar polynuclear metal complexes within columnar coordination cages are described. The reactions between hexanuclear [Au.sub.3]-[Au.sub.3] clusters and Ag(I) ions to prepare a silver-sandwiched hetero-[Au.sub.3]-Ag-[Au.sub.3] cluster are described.

Two of the free-base corroles and six manganese(III) corroles are studied by X-ray crystallography, which has included one complex that is considered a transition-state analogue of oxygen atom transfer (OAT) from (oxo)manganese(V) to thioansisole. The studies have indicated that disproportionation of the original (oxo)manganese(V) corrole to (oxo)manganese(IV) and (oxo)manganese(VI) corroles, followed by substrate oxidation by the latter complex, has obtained importance when the direct OAT process has become less favorable.

X-ray structures of two de novo designed parallel three-stranded coiled coils designed by using the heptad repeat in their nonmetalated forms are presented. The study provides general rules for heavy metal binding to cys-rich sites in designed proteins which might be used to better understand the binding mechanism between the heavy metals and metallochaperones or metalloregulatory proteins.

The one-pot synthesis of three symmetrical macrocyclic pyridyl urea hosts is described and X-ray crystal studies are used for confirming the structures of the free hosts and their host.guest complexes with alkali metal ions. Two of the hosts have showed high affinity for LiB[F.sub.4], which is because of strong interactions between the urea oxygens and the cations with pyridine nitrogens contributing additional stabilizing interactions.

Highly soluble, PEGylated cage derivative is used for showing the full reversibility of the light-driven encapsulation/release process. X-ray structure analysis has confirmed the guest molecules having left the cavity of the host and on the contrary joining the cages into a polymeric material by binding to their Pd(II) centers from outside.

The total structure of [Au.sub.38][(S[C.sub.2][H.sub.4]Ph).sub.24] nanoparticles is determined by single crystal X-ray crystallography. The nanoparticle is based on a face-fused [Au.sub.23] biicosahedral core and the six [Au.sub.2][(SR).sub.3] staples are arranged in a staggered configuration.

The first X-ray crystal structures of [Co.sup.2+], [Fe.sup.2+] and [Mn.sup.2+] metal-substituted human histone deacetylases (HDACs), each complexed with the inhibitor M344 is reported. The results provide insight into the metal dependence of the substrate [K.sub.M] values and the [K.sub.i] values of hydroxamate inhibitors that chelate the active site metal and the affinities of metal ions that are comparable to the readily exchangeable metal concentration estimated in living cells.

A combination of X-ray crystallography, electronic absorption spectroscopy, resonance Raman spectroscopy, and bonding calculations are applied to understand the considerable thiolate-thione character possessed by the monoanionic dithiolene ligand resulting from an admixture of an intraligand charge transfer excited state into the ground state wave function. A highly versatile donor-acceptor character exhibited by the unusual dithiolene which remarkably affected the Mo(IV/V) redox couple provide insight into a potentially noninnocent role of the pterin fragment in pyranopterin Mo enzymes.

The density-functional theory computations and powder X-ray crystallography are applied to study the structural, electronic, and optical properties of the thiolate-protected [Au.sub.38][(SR).sub.24] cluster. The study demonstrated a new mechanism for the strong chiral response of thiolate-protected gold clusters with achiral metal cores and ligands.

Highly symmetrical protein cage architectures from three different iron storage proteins, heavy and light human ferritin chains (HuHFt and HuLFt) and ferritin from the hyperthemophilic bacterium Pyrococcus furiosus (PfFt) were used as models to better understand the molecular basis of silver ion deposition and metal core formation inside the protein cavity. The obtained AgNP endowed with a narrow size distribution, high stability in water solution, and high thermal stability could used for range of applications such as catalysts in water, for preparation of metamaterials, and in vivo diagnosis and antibacterial or tumor therapy.

Structural characterization of large ionic water cluster H[([H.sub.2]O).sub.28.sup.+], consisting of a water shell [([H.sub.2]O).sub.26] and an encaged species H[([H.sub.2]O).sup.2+] as a center core, trapped in the well-modulated cavity of a porous metal-organic framework (MOF) is reported. Direct observation of the structures of various large ionic water clusters trapped by porous MOFs, coupled with the proton/ion-exchange processes and the reversible dehydration/rehydration, provide valuable insights into the aqueous proton transfer and its mobility pertaining to the large protonated water clusters in the condensed phase.

New cyclobutanone analogues of penams and penems are prepared and analyzed for inhibition of class A,B,C, and D [beta]-lactamases. The cyclobutanones have represented the first type of reversible inhibitors to indicate moderate inhibition of both serine- and metallo-[beta]-lactamases and can be used for development of practical inhibitors.