ABSTRACT
A series of seven new complexes including silver-thiolate molecular clusters and their covalent supramolecular frameworks have been assembled from the silver carbide precursor Ag2 C2 using a C22- pre-templated approach. Herein, two prototype clusters Ag14 (SR)6 and CO3 @Agm (SR)10 (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, Ag14 (S-iPr)6 (CO2 CF3 )8 â (DMSO)6 (two polymorphic forms 1, 2) and [Ag14 (S-Cy)6 (CO2 CF3 )8 (DMSO)4 ]â (DMSO)3 (3), and a cluster-based metal-organic framework {Ag3 [Ag14 (S-iPr)6 (CO2 CF3 )11 (H2 O)3 CH3 OH]â (H2 O)2.5 }n (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(CH3 )2 CO]â [CO3 @Ag18 (S-tBu)10 (NO3 )7 (DMF)4 ]â DMF}n (5), as well as two layer-type compounds, namely, {Ag[CO3 @Ag20 (S-iPr)10 (CO2 CF3 )9 (CO2 HCF3 )(CH3 OH)2 ]}n (6) and {Ag2 [CO3 @Ag20 (S-Cy)10 (CO2 CF3 )10 (CO2 HCF3 )2 (H2 O)2 ]â (H2 O)3 â (CH3 OH)3 }n (7) exhibiting sql-net characteristics. It is demonstrated that the C≡C2- pre-template, which draws several Ag+ ions together to form the C2 @Agn 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.
ABSTRACT
Using a chloride-assisted supramolecular building-block approach, we have employed the molecular Cl@Agm(C[triple bond, length as m-dash]CPh)n entity in the construction of a gigantic cluster namely [Ag216S56Cl7(C[triple bond, length as m-dash]CPh)98(H2O)12][Ag3(imidazole)(H2O)4](SbF6)2 (1), which contains the largest discrete organometallic cluster investigated by X-ray crystallography. Based on an icosahedral Cl@Ag12 kernel, this spheroidal cluster features an unprecedented five-shell structure Cl@Ag12@S12@Ag32@S44Cl6@Ag172 with idealized Th symmetry. The MALDI-MS, 1D, 2D 1H 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 CH2Cl2), 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.
ABSTRACT
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.
ABSTRACT
Eight new silver(I) trifluoroacetate complexes based on a series of designed ligands, each featuring an alicyclic ring with enediyne functionality, have been synthesized and characterized by single-crystal X-ray diffraction. Each ethynide terminal is inserted into an Agn (n = 4-5) basket, leading to the generation of coordination chain or layer structures, but the well shielded ethenyl group does not take part in silver-olefin bonding. Variation in ring size of the alicycles is shown to influence the construction of the organosilver(I) coordination networks, which are consolidated by weak intermolecular interactions in the crystal structures. The effect of adding ancillary N-donor ligands to the reaction system on the coordination and supramolecular network assembly is also investigated.
