[Ag₇(H){E₂P(OR)₂}₆] (E = Se, S): Precursors for the Fabrication of Silver Nanoparticles

Abstract

Reactions of Ag(I) salt, NH(4)(E(2)P(OR)(2)) (R = (i)Pr, Et; E = Se, S), and NaBH(4) in a 7:6:1 ratio in CH(2)Cl(2) at room temperature, led to the formation of hydride-centered heptanuclear silver clusters, [Ag(7)(H){E(2)P(OR)(2)}(6)] (R = (i)Pr, E = Se (3): R = Et; E = S(4). The reaction of [Ag(10)(E){E(2)P(OR)(2)}(8)] with NaBH(4) in CH(2)Cl(2) produced [Ag(8)(H){E(2)P(OR)(2)}(6)](PF(6)) (R = (i)Pr, E = Se (1): R = Et; E = S(2)), which can be converted to clusters 3 and 4, respectively, via the addition of 1 equiv of borohydride. Intriguingly clusters 1 and 2 can be regenerated via adding 1 equiv of Ag(CH(3)CN)(4)PF(6) to the solution of compounds 3 and 4, respectively. All complexes have been fully characterized by NMR ((1)H, (77)Se, (109)Ag) spectroscopy, UV-vis, electrospray ionization mass spectrometry (ESI-MS), FT-IR, thermogravimetric analysis (TGA), and elemental analysis, and molecular structures of 3(H) and 4(H) were clearly established by single crystal X-ray diffraction. Both 3(H) and 4(H) exhibit a tricapped tetrahedral Ag(7) skeleton, which is inscribed within an E(12) icosahedron constituted by six dialkyl dichalcogenophosphate ligands in a tetrametallic-tetraconnective (μ(2), μ(2)) bonding mode. Density functional theory (DFT) calculations on the models [Ag(7)(H)(E(2)PH(2))(6)] (E = Se: 3'; E = S: 4') yielded to a tricapped, slightly elongated tetrahedral silver skeleton, and time-dependent DFT (TDDFT) calculations reproduce satisfyingly the UV-vis spectrum with computed transitions at 452 and 423 nm for 3' and 378 nm for 4'. Intriguingly further reactions of [Ag(7)(H){E(2)P(OR)(2)}(6)] with 8-fold excess amounts of NaBH(4) produced monodisperse silver nanoparticles with an averaged particle size of 30 nm, which are characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), and UV-vis absorption spectrum.

Thermochromic Luminescent Materials and Multi-Emission Bands in d10 Clusters

“…However, in the case of the “opened” cluster, there is one Cu-Cu Wiberg bond index which is one order of magnitude smaller than the others (0.009). This result allows us to confirm that for the opened cluster the d 10 -d 10 interaction is weak10112223242526.…”

TD-DFT Benchmark on Inorganic Pt(II) and Ir(III) Complexes

“…For organic molecules, and especially dyes, one may quote the extensive benchmarks performed by Jacquemin et al in the last years, showing how TD-DFT can provide accurate results for such kinds of compounds after inclusion of some specific corrections (especially accounting for solvent effects). [1][2][3][4][5][6][7][8][9][10][11][12][13][14] However, despite increasing use of the same approach for metal complexes, [15][16][17][18][19][20][21][22][23][24][25][26] or in metal cluster chemistry, [27][28][29][30] benchmarks on those compounds remain difficult to perform, especially due to the requested resources. In any case, some preliminary benchmark study provided encouraging results.…”

Synthesis, Characterization, and Reactivity of the Group 11 Hydrido Clusters [Ag6H4(dppm)4(OAc)2] and [Cu3H(dppm)3(OAc)2]

“…Consequently, Ag I -H complexes have proven to be relatively rare. 21,[23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] Moreover, the examples isolated thus far are either homometallic monohydrides, e.g., [ 10 ] 2+ ). 39 Herein, we report the synthesis and characterization of the first structurally characterized homometallic silver polyhydrido cluster, [Ag 6 H 4 (dppm) 4 (OAc) 2 ].…”