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The first molecular structure of an alkaline-earth-metal carbene complex is presented. This calcium bis(iminophosphorno)methandiide chelate complex crystallizes as a dimer in which the carbene carbons bridge the metal centers.

The related parameters of cation size and valence that control the crystallization of Sr3CaRu2O9 into a 1:2 B-site-ordered perovksite structure were explored by cationic substitution at the strontium and calcium sites and application of high pressure. The size of calcium relative to ruthenium is a critical structure-determining factor in Sr3CaRu2O9.

By immersing ether Au(111) or Au(100) substrate into benzene ad layers of 15-crown 15-ether- substituted cobalt (II) phtalocyanine (CoCRPc) were prepared. Relationship between CRPc and Au lattice is significant in trapping of Ca(super 2+) ions in crown rings.

Quantum-chemical calculations including band structure and electron localization function (ELF) analysis are employed to study the electronic properties of [Ca.sub.2]Li[C.sub.3]H crystals generated by the reaction of carbon and Ca[H.sub.2] in a calcium/lithium flux mixture. The [Ca.sub.2]Li[C.sub.3]H structure is observed to feature the rarely seen [C.sub.3.sup.4-] carbide anion and the protolysis reaction of this compound with ammonium chloride produces [C.sub.3][H.sub.4].

The crystal growth of CaTi[O.sub.3] hollow crystals with different microstructures is examined. The formation mechanism of the hollow CaTi[O.sub.3] crystals have helped in controlling the microstructures of the materials and also explain the formation of many other hollow crystals.

Molecular dynamics techniques are used for carrying out large-scale simulations of various 25-mer sequences of ribonucleic acid (RNA) in bulk water and with aqueous montmorillonite clay over many tens of nanoseconds. Specific RNA sequences are folded to characteristic secondary structural motifs over time scales of few nanoseconds, but in aqueous [Ca.sup.2+] environments, RNA has tethered to the clay surface through a nucleotide base, leaving the 3' -end of the strand exposed, thus providing a mechanism for the regiospecific adsorption and elongation of RNA oligomer on clay surfaces.

The combination of a microcontact printing technique and fusion of lipid vesicles to create spatially organized surfaces of lipids and proteins that might mimic renal tubule surfaces are used to fabricate the patterns of phosphatidylserine (DPPS) bilayers and osteopontin (OPN) on silica substrates. The patterning protocol could also be expanded to other urinary molecules and provide a convenient approach for understanding the effects of biomolecules on COM crystal attachment and the pathogenesis of kidney stones.

The reaction of bromo-2,4,6-triphenylbenzene with calcium in varying stoichiometric ratios was used to mechanically study the formation of the stable inverse Ca(I) sandwich complex [[(thf).sub.3]Ca([mu]-[C.sub.6][H.sub.3]-1,3,5-[Ph.sub.3])Ca[(thf).sub.3]]. The modified substitution pattern of arylcalcium halides showed that phenyl substituents at the para position induce lability, leading to an enhanced tendency to cleave ethers.

Crystals of the compound [Ca.sub.3]LiOs[O.sub.6] are grown by a flux method by using LiCl and KCl, which is followed by single-crystal X-ray diffraction (XRD), low-temperature XRD, and measurements of ac and dc magnetic susceptibility and specific heat. The original superexchange magnetic path Os-O-Os is absent and hence the extended superexchange path (Os-O)-(O-Os) is responsible for the 117 K magnetic order.

Catalytic asymmetric protonation of chiral calcium enolates via 1,4-addition in the presence of catalytic amounts of Ca[(OEt).sub.2], Ph-PyBox, and achiral phenol is reported. The obtained adducts having tertiary asymmetric carbons in high yields with high enantioselectivities is readily converted to optically active 2-substituted 1,5-dicarboxylic acid derivatives.

Synthetic explorations in the Ca[Au.sub.5]-Ca[Au.sub.4]Bi-Bi[Au.sub.2] system have shown five separate solid solution regions that show three distinct substitution patterns in the Ca[Au.sub.5] parent. The DTA analyses have shown that the phases resulting from spinodal decomposition have nearly the same melting point and they are interconvertible through peritectic reactions.

Spectroscopy and crystallography are used for determining the divalent calcium and ytterbium compounds M[(C[(SiH[Me.sub.2]).sub.3]).sub.2][THF.sub.2] contain [beta]-agostic SiH groups. [beta]-Elimination is not an observed reaction pathway despite the strong hydridic character of the SiH groups and the low-coordinate, Lewis acid metal center in M[(C[(SiH[Me.sub.2]).sub.3][THF.sub.3] compounds.

Calcium benzoate trihydrate (Ca[([C.sub.6][H.sub.5]COO).sub.2].3[H.sub.2]O) is used as a model for the NMR analysis of calcium sites in biological materials, because of the similarity of its calcium coordination, to water and carboxylate ligands, to that in many calcium-proteins. The studies have shown that despite the weakness of [super 13]C-[super 43]Ca interactions, it is possible to discriminate carbon atoms according to their calcium environment.

The characterization of the rock-salt type [Ca.sub.1-x][Mn.sub.x][O.sub.2] solid solution by the transmission electron microscopy has shown the existence of subtle extra ordering in other upper oxides of the Ca-Mn-O system. The combination of electron microscopy with powder X-ray and neutron diffraction has allowed a complete characterization of the system.

The chiral calcium species prepared from calcium isopropoxide and chiral bisoxazoline ligands were used to develop the catalytic asymmetric 1,4-addition and [3+2] cycloaddition reactions. The findings revealed that the reaction produced to several kinds of optically active substituted pyrrolidine derivatives such as 3-substituted glutamic acid containing contiguous stereogenic tertiary and quaternary carbon centers with high diastereo- and enantioselectivities.

The microscopic studies of peptide phosphoprotein osteopontin (OPN) and calcium oxalate monohydrate (COM) crystal are reported. The results provide insight into the significant role of phosphate and carboxylate groups in a phosphoprotein-biomineral interaction.

The structural evolution of the self-assembled monolayer (SAM) and mineral are analyzed by examining the changes in order and bonding of mercaptophenol (MP) SAMs on Au(111) during the initial stages of mineral formation as well as the mechanism of amorphous calcium carbonate (ACC) to calcite transformation during template-directed crystallization. A preferential face of nucleation is seen for crystallization of calcite from ACC on the SAM surfaces despite the static structural disorder.

The adsorption of Calcium (Ca) on pristine and electron-irradiated poly surfaces is studied quantitatively to analyze the energy of adsorption, amount of Ca absorbed. The exposure of poly surfaces to electrons increases the initial sticking probability of Ca, but decreases its absorption energy.

The design, synthesis and the biological utility of BiNiX, a photoactivatable ryanodine receptor (RyR) agonist, is reported. Focal photolysis has permitted activation of RyRs with high spatiotemporal precision, thereby indicating that BiNiX is a unique tool for probing RyR function in living cells.

The single-crystal X-ray diffraction technique is employed to analyze and report the structure and bonding the new transition-metals, namely [Ca.sub.2]Cd[Sb.sub.2] and [Yb.sub.2]Cd[Sb.sub.2], wherein the cation-anion interactions are found to be the structure driving factors. The results show that such structures exhibit narrow gap semiconducting and poor metallic behavior, as the inversion symmetry is absent in this case.

Spin-based magnetic molecular species are designed based on the exotic planar tetracoordinated carbon (ptC) radical C[Al.sub.3]Si and their spins are determined by the PtC radical (C[Al.sub.3]Si)-decks. The heterodecked sandwich scheme is testified to be an effective way to capture planar radicals and to design spin-based molecular materials.

The crystal structures of the calcium-bound con-G and con-T[K7[gamma]] dimeric short peptides at atomic resolution are explored. Results that the con-G dimer interface is completely different from the con-T[K7[gamma]] interface even though the metal chelation is similar in both the peptides.

A genetic toolbox of natural and engineered protein modules is used to create several materials that form reversible networks in the presence of [Ca.sup.2+]. The modular framework can be extended to create a variety of new sensing materials using modules from the diverse array of signaling pathways that are mediated by reversible protein-protein interactions.

Data from a high-resolution EXAFS method using a novel multicrystal monochromator is presented. It is concluded that two Mn-Mn distances of 2.73 and 2.82 angstrom in a 2:1 ratio can be resolved using this method, proving the presence of three short Mn-Mn vectors in the S1 and S2 states of the Mn4Ca cluster.

The successful design of a Ca(super 2+)- binding site in the non-Ca(super 2+)- binding cell adhesion protein CD2 is demonstrated. The designed protein, Ca.CD2, exhibits selectivity for Ca(super 2+) versus other di- and monovalent cations.