Anion templating from a silver(i) dithiophosphate 1D polymer forming discrete cationic and neutral octa- and decanuclear silver(i) clusters.

We report on a Ag5 coordination polymer and discrete Ag8 and Ag10 dithiophosphate clusters. The cluster formation and structures were affected by the stoichiometric control of the M : L molar ratios used. The cluster [Ag5{S2P(O(i)Pr)2}4]n(PF6)n, , is a monomeric unit within a coordination polymer formed through the reaction between [Ag(CH3CN)4]PF6 and the dithiophosphate ligand, [S2P(O(i)Pr)2](-), used in a M : L molar ratio of 5 : 4.

Reversible phase transitions within self-assembled fibrillar networks of (R)-18-(n-alkylamino)octadecan-7-ols in their carbon tetrachloride gels.

The CCl(4) gel phases of a series of low-molecular-mass organogelators, (R)-18-(n-alkylamino)octadecan-7-ols (HSN-n, where n = 0-5, 18 is the alkyl chain length), appear to be unprecedented in that the fibrillar networks of some of the homologues undergo thermally reversible, gel-to-gel phase transitions, and some of those transitions are evident as opaque-transparent changes in the appearance of the samples. The gels have been examined at different concentrations and temperatures by a wide variety of spectroscopic, diffraction, thermal, and rheological techniques. Analyses of those data and data from the neat gelators have led to an understanding of the source of the gel-to-gel transitions.

Reduction-sensitive, robust vesicles with a non-covalently modifiable surface as a multifunctional drug-delivery platform.

The design and synthesis of a novel reduction-sensitive, robust, and biocompatible vesicle (SSCB[6]VC) are reported, which is self-assembled from an amphiphilic cucurbit[6]uril (CB[6]) derivative that contains disulfide bonds between hexaethylene glycol units and a CB[6] core. The remarkable features of SSCB[6]VC include: 1) facile, non-destructive, non-covalent, and modular surface modification using exceptionally strong host-guest chemistry; 2) high structural stability; 3) facile internalization into targeted cells by receptor-mediated endocytosis, and 4) efficient triggered release of entrapped drugs in a reducing environment such as cytoplasm. Furthermore, a significantly increased cytotoxicity of the anticancer drug doxorubicin to cancer cells is demonstrated using doxorubicin-loaded SSCB[6]VC, the surface of which is decorated with functional moieties such as a folate-spermidine conjugate and fluorescein isothiocyanate-spermidine conjugate as targeting ligand and fluorescence imaging probe, respectively.

Anion-templated syntheses of octanuclear silver clusters from a silver dithiophosphate chain.

Extended chain polymers [Ag(5){S(2)P(OEt)(2)}(4)(PF(6))](n), (1) could be converted to clusters of the type, [Ag(8)(X){S(2)P(OEt)(2)}(6)](PF(6)) [X = F (2); Cl (3); H (4)], by the addition of appropriate anions, of which [Ag(8)(H){S(2)P(OEt)(2)}(6)](+) showed a unique tetracapped-tetrahedral Ag(8) core and contained Ag-mu-H-Ag linkages.

Synthesis and characterization of [Pb{Se2P(OiPr)2}2]n pseudo polymorphs: polymeric, single source precursor enabling preparation of shape-controlled lead selenide structures.

Novel lead pseudo polymorphs supported by diselenophosphate (dsep) ligands, [Pb{Se(2)P(O(i)Pr)(2)}(2)](n) (1alpha and 1beta), were synthesized and structurally characterized. The two structures differed in the binding modes of the dsep ligand. Each repeating unit in 1alpha was composed of a lead atom coordinated by two dsep ligands, one in a chelating mode and the other in a bridging-dangling mode.

Stable silver(I) hydride complexes supported by diselenophosphate ligands.

The first stable structure of silver(I) cluster cations [Ag(8)(mu(4)-H){Se(2)P(OR)(2)}(6)](+) [R = (i)Pr, 1; Et, 2] containing Ag(I)-hydride bridges (Ag-mu-H-Ag) in T symmetry was reported. The clusters having an interstitial hydride were composed of an octanuclear silver core in tetracapped tetrahedral geometry, which was inscribed within a Se(12) icosahedron represented by six dialkyl diselenophosphate ligands in a tetrametallic-tetraconnective (mu(2), mu(2)) bonding mode. The presence of hydride was unequivocally corroborated by both (1)H and (109)Ag NMR spectroscopies of which a nonet in the (1)H NMR spectrum for the hydride resonance coupled with a doublet peak observed in the (109)Ag NMR spectrum clearly suggests that eight silver nuclei are equivalent in the NMR time scale and a fast exchange of the positions between the vertex and capping silver atoms in solution must occur.

Octanuclear copper(I) clusters inscribed in a Se(12) icosahedron: anion-induced modulation of the core size and symmetry.

Synthesis and structural characterization of an octanuclear Cu(I) cluster [Cu(8){Se(2)P(O(i)Pr)(2)}(6)](PF(6))(2) (1) with an empty Cu(8) cubic core involving diisopropyl diselenophosphate (dsep) ligand has been demonstrated despite its high tendency to abstract anions even from the traces of impurities in the solvent. Reaction of 1 with anion sources (Bu(4)NF for F(-); NaBH(4) for H(-), and NaSH for S(2-)) in a 1:1 ratio produced anion-centered Cu(8) clusters with a formula [Cu(8)(X){Se(2)P(O(i)Pr)(2)}(6)](PF(6)) (X = F, 2a; H, 3a; D, 3a') and [Cu(8)(S){Se(2)P(O(i)Pr)(2)}(6)] (4) in high yields. In addition, fluoride- and hydride-centered Cu(8)(I) clusters [Cu(8)(X){Se(2)P(OEt)(2)}(6)](PF(6)) (X = F, 2b; H, 3b) could be generated in approximately 80% yield by direct reaction of [Cu(CH(3)CN)(4)](PF(6)), NH(4)Se(2)P(OEt)(2), and the anion sources (Bu(4)NF for F(-); NaBH(4) for H(-)) in 8:6:1 ratio.

Conjugate base of a secondary phosphine selenide [P(Se)(O(i)Pr)2]- as the bridging unit for the construction of heterometallic Fe(II)-Hg(II)/Cd(II) complexes.

Reactions of perchlorate salts of Hg(II)/Cd(II) with [CpFe(CO)(2)P(Se)(O(i)Pr)(2)] (denoted as L) produced dicationic clusters [HgL(2)](ClO(4))(2), 1; [HgL(3)](ClO(4))(2), 2; and [CdL(3)(H(2)O)](ClO(4))(2), 11. However, the reactions of L with Hg(II)/Cd(II) halides yielded neutral complexes. For instance, HgI(2) produced [Hg(3)I(6)L(2)], 3, or [HgI(2)L(2)], 4, depending on the metal-to-ligand ratio used.

Facile entrapment of a hydride inside the tetracapped tetrahedral Cu(I)8 cage inscribed in a S12 icosahedral framework.

Reaction of [Cu(CH(3)CN)(4)](PF(6)) and NH(4)[S(2)P(OR)(2)] in a 4:3 ratio in acetone at room temperature produces octanuclear dicationic copper complexes [Cu(8){S(2)P(OR)(2)}(6)](PF(6))(2) (R = (i)Pr, 1; Et, 3) in 81 and 83% yields, respectively. On the other hand, reaction of [Cu(CH(3)CN)(4)](PF(6)), NH(4)[S(2)P(OR)(2)], and NaBH(4) in an 8:6:1 molar ratio in THF for 1 h yields [Cu(4)(H)(mu(3)-Cu)(4){S(2)P(OR)(2)}(6)](PF(6)) (R = (i)Pr, 2a; Et, 4a) in 87 and 82% yields, respectively. In a similar reaction when NaBD(4) is used instead of NaBH(4), [Cu(4)(D)(mu(3)-Cu)(4){S(2)P(OR)(2)}(6)](PF(6)) (R = (i)Pr, 2b; Et, 4b) are obtained in 83 and 78% yields, respectively.

The coordination chemistry of selenophosphite ligands. Synthesis and characterization of heterometallic tetranuclear clusters [M{CpFe(CO)(2)P(Se)(OR)(2)}(3)](PF(6)) (M = Cu, Ag; R = (n)Pr, (i)Pr) and [Cu(mu-X) {CpFe(CO)(2)P(Se)(O(i)Pr)(2)}](2) (X = Cl, Br).

A neutral selenium donor ligand, [CpFe(CO)(2)P(Se)(OR)(2)] is used for the construction of Cu(I) and Ag(I) complexes with a well-defined coordination environment. Four clusters [M{CpFe(CO)(2)P(Se)(OR)(2)}(3)](PF(6)), (where M = Cu, R = (n)Pr, ; R = (i)Pr, and M = Ag, R = (n)Pr, ; R = (i)Pr, ) are isolated from the reaction of [M(CH(3)CN)(4)(PF(6))] (where M = Cu or Ag) and [CpFe(CO)(2)P(Se)(OR)(2)] in a molar ratio of 1 : 3 in acetonitrile at 0 degrees C. The reaction of [CpFe(CO)(2)P(Se)(O(i)Pr)(2)] with cuprous halides in acetone produce two mixed-metal, Cu(I)(2)Fe(II)(2) clusters, [Cu(mu-X) {CpFe(CO)(2)P(Se)(O(i)Pr)(2)}](2) (X = Cl, ; Br, ).

Phosphonate- and ester-substituted 2-cyanoethylene-1,1-dithiolate clusters of zinc: aerial CO2 fixation and unusual binding patterns.

Treatment of [Zn(tmeda)Cl2] (tmeda = N, N, N', N'-tetramethylethylenediamine) with a phosphonate-substituted 2-cyanoethylene-1,1-dithiolato ligand in air yields a tetranuclear zinc-carbonate complex 1 having the formula of [Zn4(tmeda)3(mu3-CO3){S2CC(CN)P(O)(OEt)2}3] in which four zinc atoms form a trigonal pyramid with the apical zinc atom in a hitherto unknown S3O3 coordination sphere. It is the first example of aerial CO2 fixation to afford a metal-carbonato compound incorporating 1,1-ethenedithiolate ligands. In sharp contrast, reaction with an isobutyl ester-substituted 2-cyanoethylene-1,1-dithiolate forms a trimeric zinc complex [Zn(tmeda){S2CC(CN)(CO2(i)Bu)}]3, 2, which does not contain the metal-bound carbonate.

Metal binding characteristics of a laterally nonsymmetric aza cryptand upon functionalization with a pi-acceptor group.

The laterally nonsymmetric aza cryptand synthesized by condensing tris(2-aminoethyl)amine (tren) with tris[[2-(3-(oxomethyl)phenyl)oxy]ethyl]amine readily forms mononuclear inclusion complexes with both transition and main-group metal ions. In these complexes, the metal ion occupies the tren-end of the cavity making bonds with the three secondary amino and the bridgehead N atoms. When a strong pi-acceptor group such as 2,4-dinitrobenzene is attached to one of the secondary amines, the binding property of the cryptand changes drastically.