Two new semiconducting zinc coordination polymers, Zn(8)S(SPh)(14)(bpy) (1) and Zn(2)(SPh)(4)(bpy) (2), have been synthesized by a dual-ligand approach. Single-crystal structural analyses indicate that compound 1 has a helical-chain structure with P1 clusters bridging with bipyridyl (bpy) ligands and compound 2 possesses a layered structure with zinc sulfide chains cross-linked with bpy ligands. The diffuse-reflectance spectra reveal that the band gaps of the two compounds are 2.41 eV for 1 and 2.56 eV for 2.
Inexpensive 1,1'-thiocarbonyldiimidazole and di(2-pyridyl) thionocarbonate have been used as respective sulfide precursors to assemble unprecedented high-nuclearity ethynide-stabilized silver(i) sulfido molecular clusters [Ag9S6@Ag36(C[triple bond, length as m-dash]C(t)Bu)32(H2O)2] [Ag(imidazole)(CH3OH)(H2O)](BF4)2·8H2O·2CH3OH (1) and [Ag120S24(PhC[triple bond, length as m-dash]C)52Cl4(2-pyridone)10(H2O)8](H3O)4(SiF6)8(BF4)4·CH3OH·22H2O (2), the latter being the largest isolated silver(i) ethynide cluster reported to date.
A series of seven new complexes including silver-thiolate molecular clusters and their covalent supramolecular frameworks have been assembled from the silver carbide precursor Ag C using a C pre-templated approach. Herein, two prototype clusters Ag (SR) and CO @Ag (SR) (R=isopropyl, cyclohexyl or tert-butyl; m=18 or 20) are employed to construct cluster-based metal-organic frameworks of different dimensions. In particular, both new ellipsoidal tetradecanuclear molecular cluster compounds, namely, Ag (S-iPr) (CO CF ) ⋅(DMSO) (two polymorphic forms 1, 2) and [Ag (S-Cy) (CO CF ) (DMSO) ]⋅(DMSO) (3), and a cluster-based metal-organic framework {Ag [Ag (S-iPr) (CO CF ) (H O) CH OH]⋅(H O) } (4) have been isolated and structurally characterized. Furthermore, increased acidity of the reaction mixture afforded three carboxylate-templated cluster based frameworks: a chain-like compound {[HN(CH ) CO]⋅[CO @Ag (S-tBu) (NO ) (DMF) ]⋅DMF} (5), as well as two layer-type compounds, namely, {Ag[CO @Ag (S-iPr) (CO CF ) (CO HCF )(CH OH) ]} (6) and {Ag [CO @Ag (S-Cy) (CO CF ) (CO HCF ) (H O) ]⋅(H O) ⋅(CH OH) } (7) exhibiting sql-net characteristics. It is demonstrated that the C≡C pre-template, which draws several Ag ions together to form the C @Ag entity, plays an indispensable role in the syntheses of these compounds. Furthermore, covalent linkage of these nano-sized silver thiolate clusters from one- to three-dimensions revealed enormous potential for the future development of silver cluster-based frameworks.
Using a chloride-assisted supramolecular building-block approach, we have employed the molecular Cl@Ag(C[triple bond, length as m-dash]CPh) entity in the construction of a gigantic cluster namely [AgSCl(C[triple bond, length as m-dash]CPh)(HO)][Ag(imidazole)(HO)](SbF) (1), which contains the largest discrete organometallic cluster investigated by X-ray crystallography. Based on an icosahedral Cl@Ag kernel, this spheroidal cluster features an unprecedented five-shell structure Cl@Ag@S@Ag@SCl@Ag with idealized T symmetry. The MALDI-MS, 1D, 2D H NMR, electronic absorption, emission spectra and HR-TEM of 1 were measured. Compound 1 shows intense red luminescence in solution at room temperature (QY = 4.7% in CHCl), in addition to its 3.4 nm diameter, which makes it a unique example that fills the gap between small luminescent silver clusters and large luminescent silver nanoparticles.
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