Surface modifications of eight-electron palladium silver superatomic alloys.

Atomically precise thiolate-protected coinage metal nanoclusters and their alloys are far more numerous than their selenium congeners, the synthesis of which remains extremely challenging. Herein, we report the synthesis of a series of atomically defined dithiophosph(in)ate protected eight-electron superatomic palladium silver nanoalloys [PdAg{SPR}], 2a-c (where R = OPr, a; OBu, b; Ph, c) via ligand exchange and/or co-reduction methods. The ligand exchange reaction on [PdAg{SP(OPr)}], 1, with [NH{SePR}] (where R = OPr, or OPr) leads to the formation of [PdAg{SeP(OPr)}] (3) and [PdAg{SeP(OPr)}] (4), respectively.

Polyhydrido Copper Nanoclusters with a Hollow Icosahedral Core: [Cu H {E P(OR) } ] (E=S or Se; R=nPr, iPr or iBu).

Although atomically precise polyhydrido copper nanoclusters are of prime interest for a variety of applications, they have so far remained scarce. Herein, this work describes the synthesis of a dithiophosphate-protected copper(I) hydride-rich nanocluster (NC), [Cu H {S P(OnPr) } ] (1 ), fully characterized by various spectroscopic methods and single-crystal X-ray diffraction. The X-ray structure of 1 reveals an unprecedented central Cu hollow icosahedron.

Mono- and hexa-palladium doped silver nanoclusters stabilized by dithiolates.

The synthesis, via a co-reduction method, of the first Pd-containing silver-rich 21-metal-atom nanocluster passivated by dithiolates, [PdAg20{S2P(OnPr)2}12] (1), is reported. 1 is an 8 electron superatom isoelectronic to [Ag21{S2P(OiPr)2}12]+. The doping of Pd in 1 leads to its high stability against degradation in solution and shows red emission in MeTHF at 77 K.

Electron Precise Group 5 Dimetallaheteroboranes [{CpV(μ-EPh)}{μ-η:η-BHE}] and [{CpNb(μ-EPh)}{μ-η:η-BHE}] (E = S or Se).

Synthesis and structural elucidation of various electron precise group 5 dimetallaheteroboranes have been described. Room temperature reaction of [CpVCl] with Li[BH(EPh)], generated from the treatment of LiBH·THF and PhE (E = S or Se), for 1 h in toluene, followed by thermolysis, led to the formation of bimetallic complexes [{CpV(μ-EPh)}{μ-η:η-BHE}], 1 and 2 (1: E = S and 2: E = Se), and [{CpV(μ-SePh)}{μ-η:η-BH(OCH)Se}], 3. One of the striking features of these compounds is that they represent a rare class of distorted tetrahedral clusters having bridging hydrogens.

Template-Free Assembly in Living Bacterial Suspension under an External Electric Field.

Although template-assisted self-assembly methods are very popular in materials and biological systems, they have certain limitations such as lack of tunability and switchable functionality because of the irreversible association of cells and their matrix components. With an aim to achieve more tunability, we have made an attempt to investigate the self-assembly behavior of rod-shaped living bacteria subjected to an external alternating electric field using confocal microscopy. We demonstrate that rod-shaped living bacteria dispersed in a low salinity aqueous medium form different types of reversible freely suspended structures when subjected to an external alternating electric field.

Synthesis, Chemistry, and Electronic Structures of Group 9 Metallaboranes.

Dimetallaoctaborane(12) of Ru, Co, and Rh have been well-characterized by a range of spectroscopic techniques and X-ray diffraction studies. Thus, reinvestigation of the Ir-system became of interest. As a result, a slight modification in the reaction conditions enabled us to isolate the missing Ir analogue of octaborane(12), [(Cp*Ir)BH], 1.

Synthesis and chemistry of the open-cage cobaltaheteroborane cluster [{(η(5)-C5Me5)Co}2B2H2Se2]: a combined experimental and theoretical study.

Reaction of [(η(5)-C5Me5)CoCl]2 with a two-fold excess of [LiBH4·thf] followed by heating with an excess of Se powder produces the dicobaltaselenaborane species [{(η(5)-C5Me5)Co}2B2H2Se2], , in good yield. The geometry of resembles a nido pentagonal [Co2B2Se2] bipyramid with a missing equatorial vertex. It can alternatively be seen as an open cage triple-decker cluster.

Chemistry of group 9 dimetallaborane analogues of octaborane(12).

We report the synthesis, isolation and structural characterization of several moderately air stable nido-metallaboranes that represent boron rich open cage systems. The reaction of [Cp*CoCl]2, (Cp* = η(5)-C5Me5), with [BH3·thf] in toluene at ice cold temperature, followed by thermolysis in boiling toluene produced [(Cp*Co)B9H13], 1 [(Cp*Co)2B8H12], 2 and [(Cp*Co)2B6H10] 3. Building upon our earlier reactivity studies on rhodaboranes, we continue to explore the reactivity of dicobalt analogues of octaborane(12) cluster 3 with [Fe2(CO)9] and [Ru3(CO)12] at ambient conditions that yielded novel fused clusters [Fe2(CO)6(Cp*Co)2B6H10], 4 and [Ru4(CO)11(Cp*Co)2B3H3], 5 respectively.

Metallaboranes from Metal Carbonyl Compounds and Their Utilization as Catalysts for Alkyne Cyclotrimerization.

The photolysis of [M (CO) ] (M=Re or Mn) with BH ⋅thf at room temperature yields arachno-1 and 2, [(CO) M B H ] (1: M=Re, 2: M=Mn). Both the compounds show a butterfly structure with seven skeletal electron pairs and 42 valence electrons. This result presents a new method for general access to low-boron-content metal-boron compounds without the cyclopentadienyl ligand at the metal centers.

A novel heterometallic μ9-boride cluster: synthesis and structural characterization of [(η(5)-C5Me5Rh)2{Co6(CO)12}(μ-H)(BH)B].

The preparation, characterization, and electronic structure of the first heterometallic μ9-boride cluster [(Cp*Rh)2{Co6(CO)12}(μ-H)(BH)B)] has been reported. The interstitial boron atom in the title cluster is within the bonding contact of eight metal and one boron atom in a unique tricapped trigonal prism geometry.

New heteronuclear bridged borylene complexes that were derived from [{Cp*CoCl}2] and mono-metal-carbonyl fragments.

The synthesis, structural characterization, and reactivity of new bridged borylene complexes are reported. The reaction of [{Cp*CoCl}2] with LiBH4·THF at -70 °C, followed by treatment with [M(CO)3(MeCN)3] (M=W, Mo, and Cr) under mild conditions, yielded heteronuclear triply bridged borylene complexes, [(μ3-BH)(Cp*Co)2(μ-CO)M(CO)5] (1-3; 1: M=W, 2: M=Mo, 3: M=Cr). During the syntheses of complexes 1-3, capped-octahedral cluster [(Cp*Co)2(μ-H)(BH)4{Co(CO)2}] (4) was also isolated in good yield.