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This work presents new frontal affinity chromatography (FAC) methodologies for high-throughput screening of compound libraries, designed to increase screening rates and improve sensitivity and ruggedness in performance. A FAC column constructed around the enzyme N-acetylglucosaminyltransferase V (GnT-V) was implemented in the identification of potential enzyme inhibitors from two libraries of trisaccharides. Effluent from the FAC column was fractionated, sequentially processed via LC/MS, and referenced to a similar analysis through a control FAC column lacking the enzyme. The resulting multidimensional data sets were compared across corresponding sample and control fractions to identify binders, in a semiautomated approach. A strong binder in the protonated form at m/z 795 was identified from the first library of 81 compounds, exhibiting an estimated [K.sub.d] value of 0.3 [micro]M. Other binders yielded [K.sub.d] values ranging from 0.35 to 3.35 [micro]M. To demonstrate the improvement in performance of this FAC-LC/MS approach over the conventional online FAC/MS approach, 15 compounds from this library were blended with a second library of 1000 synthetic trisaccharides and screened against GnT-V. All ligands in the 15-compound set were identified in this larger screen, and no ligands of greater affinity than compound 1 were found. Our results show that FAC-LC/MS is a reliable method for screening large compound libraries directly and useful for large-scale ligand discovery initiatives.

The synthesis of novel disaccharides containing disulfide (methyl-4-S-([beta]-D-galactopyranosyl-1'-thio) -4-thio-[alpha]-D-glucopyranoside (1)) and selenosulfide (methyl-4-Se-([beta]-D-galactopyranosyl-1'-thio) -4-seleno-[alpha]-D-glucopyranoside (2))functionalities in the interglycosidic linkages is described. The synthetic strategy relied on the reaction of a [beta]-glycosylthiosulfonate with a carbohydrate thiol or selenol nucleophile. The resulting protected [beta]-dihetero-linked disaccharides were deprotected to give the target compounds. The conformational preferences of these dihetero analogues were inferred from NOESY experiments and line-broadening effects in variable-temperature NMR spectra, and are rationalized in terres of molecular orbital theory. Low-energy conformations of these compounds can populate regions of conformational space not usually occupied by [beta]-1inked disaccharides, and offer the possibility for presentation of novel ligand topographies. Key words: disaccharides, disulfides, selenosulfides, interglycosidic linkages, conformations, MO explanation. On decrit la synthese de nouveaux disaccharides comportant des fonctionnalites disulfure (4-S-([beta]-D-galactopyranosyl-l'-thio) -4-thio-[alpha]-D-glucopyranoside de methyle (1)) et selenosulfure (4-Se-([beta]-D-galactopyranosyl -1'-thio)-4-seleno-[alpha]-D-glucopyranoside de methyle (2)) dans les liaisons interglycosidiques. La strategie de synthese se base sur la reaction d'un [beta]-glycosylthiosulfonate avec un carbohydrate comportant un nucleophile thiol ou selenol. Les disaccharides proteges a liaison [beta]-dihetero ont ete deproteges pour fournit les composes cibles. Les preferences conformationnelles de ces analogues dihetero ont ete deduites d'experiences [??] NEOSY [??] et d'effets d'elargissement de bande dans les spectres de RMN a temperature variable et elles sont rationalisees en fonction de la theorie des orbitales moleculaires. Les conformations de basse energie de ces composes occuper des regions de l'espace conformationnel qui ne sont generalement pas occupes par des disaccharides a liaisons [beta] et elles offrent la possibilite de presenter de nouvelles topographies pour les ligands. Mots cles : disaccharides, disulfures, selenosulfures, liaisons interglycosidiques, conformations, explication d'orbitales moleculaires. [Traduit par la Redaction]

The B[H.sub.3]-protected phosphinoindenyl ligand indenyl[(C[H.sub.2]).sub.2]P[Ph.sub.2]xB[H.sub.3] was used in the preparation of [([[eta].sup.5/3]:[[eta].sup.0]- indenyl[(C[H.sub.2]).sub.2]P[Ph.sub.2]xB[H.sub.3]) Ni(P[Ph.sub.3])Cl, which has been characterized by NMR spectroscopy and X-ray diffraction studies. On the other hand, all attempts at preparing the closely related complex [[eta].sup.5/3]: [[eta].sup.1]-indenyl(C[H.sub.2]).sub.2]P[Ph.sub.2])NiCl, in which the tethered phosphine moiety is coordinated to the Ni centre, were unsuccessful. One of these unsuccessful attempts yielded instead the novel indenyl-PCP pincer complex {[[kappa].sup.P],[[kappa].sup.C], [[kappa].sup.P]-1/3-[(C[H.sub.2]) C[H.sub.2]P[Ph.sub.2]).sub.2]-2-indenyl}NiCl, which has been characterized by X-ray diffraction studies. Key words: indenyl complexes, tethered phosphines, PCP pincer complexes. Le ligand protege indenyl [(C[H.sub.2]).sub.2]P[Ph.sub.2]xB[H.sub.3] a permis la preparation du compose ([eta].sup.5/3]:[[eta].sup.0] -indenyl [(C[H.sub.2]).sub.2]P[Ph.sub.2]xB[H.sub.3])Ni(P[Ph.sub.3])Cl. Ce dernier a ete completement caracterise par la spectroscopie RMN et etudes cristallographiques. Toutes les tentatives de preparer et isoler le complexe ([[eta].sup.5/3]:[[eta].sup.1]-indenyl(C[H.sub.2]).sub.2]P[Ph.sub.2])NiCl ont echoue. En revanche, nous avons obtenu lors d'une de ces tentatives un nouveau complexe inattendu; une etude cristallographique a demontre que ce dernier etait un complexe de type [??] pincer [??] PCP-indenyle, soit {[[kappa].sup.P], [[kappa].sup.C], [[kappa].sub.P] -1,3-(C[H.sub.2]C[H.sub.2]P[Ph.sub.2]).sub.2] -2-indenyl}NiCl. Mots cles : complexes d'indenyle, phosphines attachees, complexe de type [??] pincer [??] PCP.

Abstract: An extraction and sensitive differential pulse anodic stripping voltammetric (DPASV) method at a hanging mercury drop electrode (HMDE) is described for the determination of Zn, Cu, Pb ([micro]g [g.sup.1]) [...]

Highly enantioselective palladium-catalyzed asymmetric allylic alkylation using a novel chiral pyrrolidinyl-containing amino-phosphine ligands having a hydroxyl group is described. The trialkylsilylated aminophosphine ligand gave good results in the palladium-catalyzed asymmetric allylic alkylation.

The synthesis and resolution of a class of 2-substituted quinazolinap ligands for asymmetric catalysis and their application in asymmetric rhodium-catalyzed olefin hydroboration is described. Higher enantioselectivities were achieved with a 4-methoxy substituent compared to those of the 4-chloro or 4-unsubstituted analogues for styrene derivatives.

A new type of mixed-ligand Pt(II) complexes, Pt([R.sub.2]SO)(pyrazine) [Cl.sub.2], was synthesized from the aqueous reaction of K[Pt([R.sub.2] SO)[Cl.sub.3]] with pyrazine. The compounds were characterized mainly by IR and multinuclear magnetic resonance spectroscopies ([sup.1]H, [sup.13]C, and [sup.195]Pt) and crystallography. Compounds with dimethylsulfoxide, tetramethylenesulfoxide, di-n-propylsulfoxide, di-n-butylsulfoxide, dibenzylsulfoxide, and diphenylsulfoxide were studied. IR spectroscopy suggested a cis geometry for the di-n-propylsulfoxide complex and trans geometry for the other compounds. The [sup.195]Pt NMR resonances of the complexes were observed between -3042 and -3121 ppm, with that of the diphenylsulfoxide complex being at higher field than those of the others. The pyrazine [sup.3]J([sup.195]Pt-[sup.1]H) coupling constant was observed for the DMSO compound (33 Hz), suggesting a trans geometry. No J([sup.195]Pt-[sup.13]C) coupling could be detected. The crystal structures of trans-Pt(tetramethylenesulfoxide)(pyrazine) [Cl.sup.2] and of cis-Pt(di-n-propylsulfoxide)(pyrazine)[Cl.sub.2] were determined and confirmed the geometry suggested by IR and NMR spectroscopies. The compound with di-n-butylsulfoxide could not be isolated, because it rapidly formed the pyrazine-bridged dimer. Key words: platinum, sulfoxide, pyrazine, crystal structure, NMR, IR.

Reaction between 2,6-bis(2-formylphenoxymethyl)pyridine and N,N-bis(3-aminopropyl)methylamine or tris (2-aminoethyl)amine has been used as the starting point for the synthesis of seven oxa-aza macrocyclic ligands, five of them never reported previously. They all feature different pendant arms, which provide a wide range of coordination possibilities. The Schiff base macrocycles [L.sup.1] and [L.sup.4] and their reduced ligands [L.sup.2] and [L.sup.5] are derived from 2,6-bis(2-formylphenoxymethyl)pyridine and tris(2-aminoethyl)amine or N,N-bis(3-aminopropyl)methylamine, respectively. The reaction of [L.sup.1] with salicylaldehyde forms [L.sup.3], which features an imine bond in the pendant arm. The ligand [L.sup.5] has been the precursor for the pendant-armed [L.sup.6] and [L.sup.7], by alkylation of the free NH groups with methyl-imidazole or methyl-indole. By a template or a nontemplate approach, we have synthesized different mono- and dinuclear complexes with Y(III), Ln(III), Zn(II), and Cd(II) cations. Both the free macrocyclic ligands and their corresponding metal complexes have been characterized by microanalysis, IR, UV-vis, [sup.1]H and [sup.13]C NMR spectroscopy, FAB mass spectrometry, MS electrospray, and conductivity measurements. Key words: Schiff-base macrocycle, template synthesis, macrocyclic ligand complexes, lanthanide(III) complexes.

The monomeric trinitrosyl complex, W[(NO).sub.3][Cl.sub.3], can be prepared by the treatment of W[Cl.sub.6] in C[H.sub.2][Cl.sub.2] with NO gas, and its identity has been unambiguously confirmed by a single-crystal X-ray diffraction analysis. The complex crystallizes in the space group Pmn[2.sub.1] as a three-component twin (a = 10.4280(4) [Angstrom], b = 6.3289(2) [Angstrom], c = 5.6854(2) [Angstrom], Z = 2, [R.sub.1] = 0.065, w[R.sub.2] = 0.176). Its solid-state molecular structure consists of a tungsten centre bound to three chloride ligands and three linear nitrosyl ligands in a fac-octahedral stereochemistry. In addition, the structure contains a crystallographically imposed mirror plane. The two independent W--N linkages are 1.88(2) and 1.92(1) A long, while the two corresponding N--O bond lengths are 1.13(2) and 1.16(2) [Angstrom]. DFT calculations on fac-W[(NO).sub.3] [Cl.sub.3] at the B3LYP/LANL2DZ level of theory afford optimized intramolecular metrical parameters that match the X-ray crystallographically determined bond lengths and bond angles quite well. In addition, they provide a rationale for the nearly linear W-N-O linkages extant in the complex. Solutions of fac-W[(NO).sub.3] [Cl.sub.3] in C[H.sub.2] [Cl.sub.2] lose CINO under ambient conditions and deposit the well-known [W[(NO).sub.2][[Cl.sub.2]].sub.2] polymer, and this conversion is fully reversible. Key words: nitrosyl, tungsten, structure, bonding.

A new method to evaluate pore entrance size in silicas is proposed. The surface modifications method is based on the modification of the material with ligands.

Relativistic density functional theory (DFT) calculations of nitrogen hyperfine and quadrupole coupling constants are carried out for a series of oxovanadium complexes with axial and equatorial nitrogen ligands. The results carry implications for the interpretation of high-resolution electron paramagnetic resonance (EPR) spectra of oxovanadium complexes with nitrogen ligands.

We report solid-state [sup.25]Mg NMR, X-ray crystallographic, and quantum-mechanical calculation results for bis(pyridine)(5,10,15,20-tetraphenylporphyrinato)magnesium(II), Mg(TPP)*[Py.sub.2*] Mg(TPP)*[Py.sub.2] crystallizes in the triclinic form, in the space group P[bar 1]. The unit cell parameters are: a = 9.6139(13) [Angstrom], b = 11.0096(16) [Angstrom], c = 11.8656(15) [Angstrom]; [alpha] = 102.063(3)[degrees], [beta] = 103.785(3)[degrees], [gamma] = 114.043(2)[degrees]; Z = 1. The Mg(II) ion is coordinated to four nitrogen atoms from the porphyrin ring and two nitrogen atoms from the axial pyridine ligands, forming a regular octahedron. The [sup.25]Mg quadrupole coupling constant ([C.sub.Q]) is 15.32 [+ or -] 0.02 MHz, which represents the largest value so far observed for [sup.25]Mg nuclei. The electric field gradient tensor at the Mg site is axially symmetric, [[eta].sub.Q] = 0.00 [+ or -] 0.05. The [sup.25]Mg chemical shielding anisotropy is too small to be accurately determined. Quantum-mechanical calculations using a 6-31G(d) basis set reproduce reasonably well the observed [sup.25]Mg NMR data for Mg(TPP)*[Py.sub.2]. The calculations also suggest that the span of the [25.sup]Mg chemical shift tensor is less than 50 ppm. Using a theoretical approach, we also investigate the dependence of the [sup.25]Mg quadrupole coupling constant on the Mg--[N.sub.ax] bond distance. The calculation suggests that the [25.sup.Mg] quadrupole coupling constant for an Mg(II) ion at the center of a porphyrin ring without axial ligands is approximately 22 MHz, which may be treated as an upper limit of the [sup.25]Mg quadrupole coupling constant for all Mg--porphyrin complexes. Key words: [sup.25]Mg NMR, crystal structure, quantum chemical calculation, quadrupole parameter, tetraphenylporphyrin.

This paper presents a microfluidics-patch clamp platform for performing high-throughput screening and rapid characterization of weak-affinity ion channel--ligand interactions. This platform integrates a microfluidic chip consisting of multiple channels entering an open volume with standard patch clamp equipment. The microfluidic chip is placed on a motorized scanning stage and the method relies on the ability to scan rapidly, on the order of milliseconds, a patch-clamped cell across discrete zones of different solutions created in the open volume. Under ideal conditions, this method has the capacity to obtain kinetically resolved patch clamp measurements and dose--response curves of up to [10.sup.3] ligand solutions in a single day.

The parent amido complex cis-(PMe3)(sub 4)Ru(H)(NH2) has been synthesized via the deprotonation of [cis-(PMe3)(sub 4)Ru(H)(NH3)(super +)][BPh4(super -)]. The complex is slightly less basic than DMPE analogue, although it is still sufficiently basic to deprotonate fluorene, isomerize cyclohexadiene, and serve as a potent base for E2 eliminations.

The title complexes form two-demensional, distorted square grid planes with copper and halides separated by layers of tetrazole ligands. Both the complexes exhibit ferromagnetic interaction within the isolated copper-halide layers.

Synthesis of a series of aluminum complexes containing ketiminate ligands is discussed. Results reveal that the complexes are active towrd the ring-opening polymerization of epsilon-caprolactone. Furthermore, a higher molecular weight polymer results from the aluminum alkyl complexes, whereas the aluminum halide complex forms a lower molecular weight oligomer.

Research discusses the isolation and characterization of osmium complexes that involve the Schiff base diimine ligand, N-arylpyridine-2-carboxaldimine. Results reveal that the diimine in the osmium(II) center coordinated N-arylpyridine-2-carboxaldimine ligand renders it susceptible to oxidation, leading to a z+1 metal oxidation state upon oxidation of one ligand.

Results bring out the differences between the vanadium(V) complex of dihydrogen-dipic-OH and the complexes of dihydrogen-dipic in solid state and in solution. Data indicate that the differences between the dipicolinatodioxovanadate(V) parent complex and the dipic-OH complex are due to the substitutional differences in the ligands.

Results reveal that coordination of the tripyridinedimethane ligand to a copper atom prevents planarization of py-CH(sub)2-py fragments of the ligand leading to the suppression of high acididity of the methylene bridges of the free ligand.

The synthesis of three octapyrrolic, 8-10, and four dodecapyrrolic, 15-18, oligomers is reported. They are linear poly(dipyrromethene)s and potential ligands as building blocks for supramolecular architectures through self-assembly. Octapyrrolic oligomers 8-10 were prepared in 90-95% yields by condensation of 2 equiv of a tripyrrolic compound 4 with 1 equiv of diformyldipyrrolic compounds 5-7. A similar procedure, involving the condensation of 2 equiv of a pentapyrrolic starting material 13 with 1 equiv of 5-7 or 14, was found to give rise to the corresponding dodecameric systems 15-18 in 41-56% yields. Key words: poly(dipyrromethene), linear polypyrroles, dipyrromethane, dipyrromethene.

The bis-bipyridine-phosphine-oxide ligand forms complexes with Gd(sup)3+, Tb(sup)3+, and Eu(sup)3+ and the complexes exhibit anion dependent photophysical properties. Data indicate that a 7- and 11-fold increase, respectively, in the luminescence is seen when nitrate anions are added to an acetonitrile solution containing the ligand complexed with Eu and Tb ions.

Research discuss the preparation of chalcogen-rich lanthanide clusters coupled with ligands by reacting elemental E with lanthanum complexes. Data indicate that the lanthanide clusters serve as starting materials for the synthesis of larger clusters.

Results reveal that in the presence of copper(II) ion, the ligand L-histidylglycine exhibits competition between the histamine-like N-terminal part and the dipeptide backbone, which leads to a variety of coordination modes, as demonstrated by the two-dimensional electron spin resonance spectroscopy.

The design and the syntheses of four coordination silver(I) polymers capable of forming macrometallacyclic, noninterpenetrated two-dimensional networks, using 1,4-bis(phenylthio)butane as a ligand building blocks, are described. In the solid state, all the complexes exhibit either 2D honeycomb-like or lattice networks, influenced by metal-to-ligand ratio, solvents, and counteranions.

Research describes the preparation and crystal structure characterization of four ternary copper(II) complexes possessing a tridentate tris-(3-phenylpyrazolyl)borate and bidentate heterocyclic base (L). Data show a three phenyl groups of Tp(sup)Ph are spatially arranged forming a bowl-shaped structure, which encloses the {CuL} moiety.

Research delineates the structure and bonding of alkoxides in the thiolate molybdenum nitrides with other related alkoxide and thiolate nitrosyls. Results indicate that the alkoxide compounds possess weak nitride bridges, whereas the thiolate compounds exhibit weak thiolate bridges.

Myelin-associated glycoprotein (MAG) binds to the nerve cell surface and inhibits nerve regeneration. The nerve cell surface ligand(s) for MAG are not established, although sialic acid-bearing glycans have been implicated. We identify the nerve cell surface gangliosides GD1a and GT1b as specific functional ligands for MAG-mediated inhibition of neurite outgrowth from primary rat cerebellar granule neurons. MAG-mediated neurite outgrowth inhibition is attenuated by (i) neuraminidase treatment of the neurons; (ii) blocking neuronal ganglioside biosynthesis; (iii) genetically modifying the terminal structures of nerve cell surface gangliosides; and (iv) adding highly specific IgG-class antiganglioside mAbs. Furthermore, neurite outgrowth inhibition is mimicked by highly multivalent clustering of GD1a or GT1b by using precomplexed antiganglioside Abs. These data implicate the nerve cell surface gangliosides GD1a and GT1b as functional MAG ligands and suggest that the first step in MAG inhibition is multivalent ganglioside clustering.

The axial histidines of the truncated hemoglobin from Synechococcus cyanobacterium PCC 7002 serve as axial ligands to the iron. Results show that one of the vinyl side chains of the heme is involved in the hemoglobin protein's formation of covalent adduct to the side chains.

Cadherin receptors are key morphoregulatory molecules during development. To dissect their mode of action, we developed an approach based on the use of myogenic C2 cells and beads coated with an Ncad-Fc ligand, allowing us to mimic cadherin-mediated adhesion. We used optical tweezers and video microscopy to investigate the dynamics of N-cadherin anchoring within the very first seconds of bead-cell contact. The analysis of the bead movement by single-particle tracking indicated that N-cadherin molecules were freely diffusive in the first few seconds after bead binding. The beads rapidly became diffusion-restricted and underwent an oriented rearward movement as a result of N-cadherin anchoring to the actin cytoskeleton. The kinetics of anchoring were dependent on ligand density, suggesting that it was an inducible process triggered by active cadherin recruitment. This anchoring was inhibited by the dominant negative form of Rac1, but not that of Cdc42. The Rac1 mutant had no effect on cell contact formation or cadherin-catenin complex recruitment, but did inhibit actin recruitment. Our results suggest that cadherin anchoring to the actin cytoskeleton is an adhesion-triggered, Rac1 -regulated process enabling the transduction of mechanical forces across the cell membrane; they uncover novel aspects of the action of cadherins in cell sorting, cell migration, and growth cone navigation.

Cubic cage compounds composed of Co-CN-Ru linkages have been prepared which illustrate the following features: (i) new motifs for alkali metal ion complexation (i.e., cationic receptors for cations), (ii) a new family of triaza-metalloligands, and (iii) a double box-like cage. The cages are synthesized by the condensation of [[CpCo[(CN).sub.3]].sup.-] and [[Cp*Ru[(NCMe).sub.3]].sup.+] (cyclopentadienyl, Cp; pentamethylcyclopentadienyl, Cp*) the presence of [Cs.sup.+]. The species [{Cs[subset]([[CpCo[(CN).sub.3]].sub.4][[Cp*Ru].sub.4]).sup.+] and {Cs[subset][{[[CpCo[(CN).sub.3]].sub.4][[Cp*Ru].sub.3][Cp*Rh]).sup.2+] illustrate the box-completion reaction Cs [subset] [Co.sub.4][Ru.sub.3] + M (M = Cp*[Rh.sup.2+], Cp*[Ru.sup.+]). With the naked ion precursors [[Na[(NCMe).sub.6]].sup.+] and [[Fe[(NCMe).sub.6]].sup.2+], the box-completion reactions afforded [{Na[{Cs[subset][[CpCo[(CN).sub.3]].sub.4][[Cp*Ru].sub.3]]}.sub.2]}.sup.+] and [{Fe[{Cs[subset] [[CpCo[(CN).sub.3]].sub.4][[Cp*Ru].sub.3]]}.sub.2]}.sup.2+]. These cages provide the first examples, to our knowledge, of the double-box motif.

The crystal to crystal isomerization of trans-(nu(super 5)-C5H4Me)Re(CO)[P(OPh)3]Br2 provides a unique window into the mechanism of this solid-state reaction. A trivial two-atom ligand exchange (CO and Br) and not a three or four ligand turnstile or Berry-rotation pathway, and thus a two atom exchange process requires a lower activation energy relative to alternative mechanisms for the reaction.

The potentially penta-coordinating ligand [Lsup.1] has been synthesized by reaction of the bridge bis-(2(methylsulfonyl)oxyethyl)ether with the tetraazamacrocycle cyclam (cyclam = 1,4,8,11-tetraazatetradecane). The copper(II) complex was characterized initially and subsequent demetallation provided pure [L.sup.1]. Electrochemical and chemical oxidation of the nickel(II) species yields a Ni(III) ion (low-spin [d.sup.7], rhombic, [g.sub.xx] 2.195, [g.sub.yy] 2.189, [g.sub.zz] 2.027) of sufficient stability in acidic solutions for kinetic measurements to be undertaken of substitution reactions at the sixth site. The isomeric ligand [L.sup.2], has been synthesized previously, and reactions of the [[Ni([L.sup.1])(solv)].sup.3+] and [[Ni([L.sup.2])(solv)].sup.3+] ions with chloride have also been investigated. In both reactions, an unusually high acid dissociation constant is observed, associated with the proposed replacement of the apical ether oxygen by a water molecule that is bound both to the metal centre and hydrogen bonded to the ether. The structure [Ni([L.sup.2])][([PF.sub.6]).sub.2] (monoclinic, P[2.sup.1]/c, a = 10.699(2), b = 13.244(4), c = 16.603(2) [Angstrom], [beta] = 92.10(1)[degrees]) converged at R = 0.055 (R' = 0.057) for 325 parameters using 3293 reflections with I > 2[sigma](I). In this complex, the detachment of the ether O donor to yield a square-planar complex is confirmed. Comparisons are made with substitution rates at other Ni(III) macrocyclic ions. Key words: nickel(III), substitution, macrobicyclic ligand, synthesis, kinetics.

Research has been conducted on the concanavalin A. The interactions between concanavalin A and the carbohydrate-mimicking peptide ligands have been examined and the design and crystal structure analysis of the analogue complexed with concanavalin A have been reported.

Research has been conducted on the proteins of the transferrin family. The role of these proteins in the iron homeostasis in vertebrates has been investigated and discussed.

The review presents the analysis and categorization of the localization and delocalization transition in ligand-bridged mixed-violence molecules. The transition-metal complexes with the important organic results are in the main focus of the article.

Results demonstrate that the (-)-sparteine and the maleonitriledithiolate ligands donate nitrogen and sulfur to form mixed ligand systems of copper(II)(nitrogen)(sub)2(sulfur)(sub)2 complexes. Data indicate that these complexes can mimic the spectral and redox properties of the blue copper proteins.

Research explores the crystal chemistry of the interaction of an organic ligand with copper halides. Data indicate that copper(II)/dimethylbipyridine complexes are more stable than the corresponding complexes with copper(I) and copper(II) sources are the trigonal bipyramidal copper(dmbp)(sub)2bromide(sup)+ cation and the copper(dmbp)bromide complex.

The plasticity of the coordination sphere of copper(II) lends itself convenient to test the influence of other ligands on the coordination modes of heterobimetallic complexes. Research describes the syntheses, crystal structures, and variable-temperature magnetic properties of three new heterobimetallic rhenium(IV)-copper(II) complexes.

Results describe the effects of chloride, bromide, and nitrate ions on the ligand dissociation kinetics of tetradentate and bidentate (hydroxamato)iron(III) complexes. Data reveal a marked rate enhancement with chloride ion at relatively low concentrations with the effects of bromide and nitrate being lot slower.

Research describes the synthesis of an unsymmetrical binucleating ligand bearing an oxadiazole ring flanked on either side by 3-4 ligands. The binucleating ligand binds to metals forming metal complexes with metals in 5- and 6-coordinate sites.

The direct reaction of the salen ligand and Et(sub)2Zn serves as an alternative method for the preparation of zinc(II)salen-type complexes in high yield. Data indicate that the procedure is applicable to the preparation of bifunctional pyridine-modified zinc(II) bis(salicylidene) complexes as well.

Research describes synthesis of rhodium porphyrin complexes containing hydrazine ligands and analogous species with disulfide and diselenide ligands. Data show that further addition of ligands to these species lead to 1:1 complexes with ligands binding to rhodium center via the nitrogen atom.

Research demonstrates synthesis of four octanuclear organometallic squares by self-assembly between ligand complexes. Structural and elemental analyses reveal that the squares incorporate terpyridyl metal complexes as bridging ligands. All four heterometallic complexes exhibit strong visible absorption characteristic of iron, rubidium, or osmium metals.

X-ray crystal structural analyses of the three cobalt(III) complexes of the [3(sup)5]adamanzane, 1,5,9,13-tetraazabicyclo[7.7.3]nonadecane reveal that the protonated form of one of the complexes exhibit a chelate bonding mode of the hydrogen carbonate entity with a pK(sub)a value of 0.27. The protonation occurs at the noncoordinated oxygen atom of the carbonate group.

Results reveal that salts of bis(trifluoromethyl)phosphanide containing an anion [P(CF(sub)3)(sub)2](sup)- are very stable by virtue of low coordinating cations stabalizing salts with the anion.

Results show that the bipyridyl ligand 1,2-bis(2-pyridylethynyl)benzene exhibit pyridyl N atoms, which participate in trans chelation of metal cations. Crystallographic analysis of the 1:1 complex of the ligand with silver(I) triflate and palladium(II) chloride demonstrates that the ligand is essentially planar in both complexes.