Atomically precise rhodium-indium carbonyl nanoclusters: synthesis, characterization, crystal structure and electron-sponge features.

In this paper we present the investigation of the reactivity of [Rh(CO)] with InCl, with the aim of expanding the more general study that allowed us to obtain, among other species, the icosahedral [RhE(CO)] ( = 4 when E = Ge or Sn; = 3 when E = Sb or Bi) family of clusters. Indeed, the study resulted in the isolation and characterization of the analogous In-centred icosahedral [RhIn(CO)] nanocluster (1), which is isoelectronic and isostructural with the [RhE(CO)] congeners. During the course of the reaction two more new species, namely the octahedral [Rh(CO)InCl] (2) and the dimeric [{Rh(CO)InCl}] (3) have also been identified.

Multi-elemental analysis of commercial wheat flours by ICP-MS triple quadrupole in function of the milling degree.

This preliminary study is focused on an elemental analysis of 60 samples of different commercial grains' flour, including various typologies of refined product, researching transition metals and trace elements. All the samples were first digested with a microwave digestion system and then analyzed by a triple quadrupole (TQ) inductively coupled plasma mass spectrometer (ICP-MS-QQQ) located in a Clean Room ISO class 6. The minimum value of most of the elements (Li, Be, Na, Ca, V, Cr, Mn, Fe, Co, Ni, Zn, Ga, As, Se, Rb, Sr) are in the wheat flour "00" type and in the wheat flour "0" type (B, Na, Mg, Al, Cu, Ag, Cd, In, Cs, Pb, Bi).

Peraurated ruthenium hydride carbonyl clusters: aurophilicity, isolobal analogy, structural isomerism, and fluxionality.

The stepwise addition of increasing amounts of Au(PPh)Cl to [HRu(CO)] (1) results in the sequential formation of [HRu(CO)(AuPPh)] (2), [HRu(CO)(AuPPh)] (3), and HRu(CO)(AuPPh) (4). Alternatively, 4 can be obtained upon addition of HBF·EtO (two mole equivalents) to 3. Further addition of acid to 3 (three mole equivalents) results in the formation of the tetra-aurated cluster Ru(CO)(AuPPh) (5).

Highly Reduced Ruthenium Carbide Carbonyl Clusters: Synthesis, Molecular Structure, Reactivity, Electrochemistry, and Computational Investigation of [RuC(CO)].

The reaction of [RuC(CO)] () with NaOH in DMSO resulted in the formation of a highly reduced [RuC(CO)] (), which was readily protonated by acids, such as HBF·EtO, to [HRuC(CO)] (). Oxidation of with [CpFe][PF] or [CH][BF] in CHCN resulted in [RuC(CO)(CHCN)] (), which was quantitatively converted into after exposure to CO atmosphere. The reaction of with a mild methylating agent such as CHI afforded the purported [RuC(CO)(COCH)] ().

From M to M, M and M molecular alloy Pt-Ni carbonyl nanoclusters: selective growth of atomically precise heterometallic nanoclusters.

Heterometallic Chini-type clusters [PtNi(CO)] ( = 0-6) were obtained by reactions of [Pt(CO)] with Ni-clusters such as [Ni(CO)], [Ni(CO)] and [HNi(CO)], or from [Pt(CO)] and [Ni(CO)]. The Pt/Ni composition of [PtNi(CO)] ( = 0-6) depended on the nature of the reagents employed and their stoichiometry. Reactions of [Pt(CO)] with [Ni(CO)] and [HNi(CO)], as well as reactions of [Pt(CO)] with [Ni(CO)], [Ni(CO)] and [HNi(CO)], afforded [PtNi(CO)] ( = 0-9) species.

2-D Molecular Alloy Ru-M (M = Cu, Ag, and Au) Carbonyl Clusters: Synthesis, Molecular Structure, Catalysis, and Computational Studies.

The reactions of [HRu(CO)] () with M(I) (M = Cu, Ag, and Au) compounds such as [Cu(CHCN)][BF], AgNO, and Au(EtS)Cl afford the 2-D molecular alloy clusters [CuRu(CO)] (), [AgRu(CO)] (), and [AuRu(CO)] (), respectively. The reactions of with PPh result in mixtures of products, among which [CuRu(CO)] (), Ru(CO)(CuPPh) (), Ru(CO)(AgPPh) (), Ru(CO)(PPh) (), and HRu(OH)(CO)(PPh) () have been isolated and characterized. The molecular structures of and have been determined by single-crystal X-ray diffraction.

Atomically Precise Platinum Carbonyl Nanoclusters: Synthesis, Total Structure, and Electrochemical Investigation of [Pt(CO)] Displaying a Defective Structure.

The molecular Pt nanocluster [Pt(CO)] () was obtained by thermal decomposition of [Pt(CO)] in tetrahydrofuran under a H atmosphere. The reaction of with increasing amounts of HBFEtO afforded the previously reported [Pt(CO)] () and [Pt(CO)] (). The new nanocluster was characterized by IR and UV-visible spectroscopy, single-crystal X-ray diffraction, direct-current superconducting quantum interference device magnetometry, cyclic voltammetry, IR spectroelectrochemistry (IR SEC), and electrochemical impedance spectroscopy.

Inverted Ligand Field in a Pentanuclear Bow Tie Au/Fe Carbonyl Cluster.

Gold chemistry has experienced in the last decades exponential attention for a wide spectrum of chemical applications, but the +3 oxidation state, traditionally assigned to gold, remains somewhat questionable. Herein, we present a detailed analysis of the electronic structure of the pentanuclear bow tie Au/Fe carbonyl cluster [Au{η-Fe(CO)}] together with its two one-electron reversible reductions. A new interpretation of the bonding pattern is provided with the help of inverted ligand field theory.

Atomically Precise Ni-Pd Alloy Carbonyl Nanoclusters: Synthesis, Total Structure, Electrochemistry, Spectroelectrochemistry, and Electrochemical Impedance Spectroscopy.

The molecular nanocluster [NiPd(CO)] ( = 0.41) () was obtained from the reaction of [NMe(CHPh)][Ni(CO)] with 0.8 molar equivalent of [Pd(CHCN)][BF] in tetrahydrofuran (thf).

Heterometallic rhodium clusters as electron reservoirs: Chemical, electrochemical, and theoretical studies of the centered-icosahedral [RhE(CO)] atomically precise carbonyl compounds.

In this paper, we present a comparative study of the redox properties of the icosahedral [RhE(CO)] (n = 4 when E = Ge or Sn and n = 3 when E = Sb or Bi) family of clusters through in situ infrared spectroelectrochemistry experiments and density functional theory computational studies. These clusters show shared characteristics in terms of molecular structure, being all E-centered icosahedral species, and electron counting, possessing 170 valence electrons as predicted by the electron-counting rules, based on the cluster-borane analogy, for compounds with such metal geometry. However, in some cases, clusters of similar nuclearity, and beyond, may show multivalence behavior and may be stable with a different electron counting, at least on the time scale of the electrochemical analyses.

One-pot atmospheric pressure synthesis of [HRu(CO)].

Reductive carbonylation of RuCl3·3H2O at CO-atmospheric pressure results in the [H3Ru4(CO)12]- (1) polyhydride carbonyl cluster. The one-pot synthesis involves the following steps: heating RuCl3·3H2O at 80 °C in 2-ethoxyethanol for 2 h, addition of three equivalents of KOH, heating at 135 °C for 2 h, addition of a fourth equivalent of KOH and heating at 135 °C for 1 h. The resulting K[1] salt is transformed into [NEt4][1] upon metathesis with [NEt4]Br in H2O.

Heterometallic Ni-Pt Chini-Type Carbonyl Clusters: An Example of Molecular Random Alloy Clusters.

The direct reactions of homometallic [Ni(CO)] and [Pt(CO)] Chini carbonyl clusters result in heterometallic Ni-Pt Chini-type clusters of the general formula [PtNi(CO)] ( = 0-6). Their molecular structures have been determined by single-crystal X-ray diffraction (SC-XRD), showing a common octahedral (staggered, ) structure analogous to that of [Ni(CO)], whereas [Pt(CO)] displays a trigonal-prismatic (eclipsed, ) structure. This structural change after replacing one single Pt with Ni may be classified as an alloying effect, and it has been theoretically investigated by DFT methods.

Polymerization Isomerism in Co-M (M = Cu, Ag, Au) Carbonyl Clusters: Synthesis, Structures and Computational Investigation.

The reaction of [Co(CO)] () with M(I) compounds (M = Cu, Ag, Au) was reinvestigated unraveling an unprecedented case of polymerization isomerism. Thus, as previously reported, the trinuclear clusters [M{Co(CO)}] (M = Cu, ; Ag, ; Au, ) were obtained by reacting with M(I) in a 2:1 molar ratio. Their molecular structures were corroborated by single-crystal X-ray diffraction (SC-XRD) on isomorphous [NEt][M{Co(CO)}] salts.

Structural Diversity in Molecular Nickel Phosphide Carbonyl Nanoclusters.

The reaction of [Ni(CO)] as a [NBu] salt in CHCl with 0.8 equiv of PCl afforded [NiP(CO)]. In contrast, the reactions of [Ni(CO)] as a [NEt] salt with 0.

Synthesis, Structural Characterization, and DFT Investigations of [MM'Fe(CO)] (M, M' = Cu, Ag, Au; M ≠ M') 2-D Molecular Alloy Clusters.

Miscellaneous 2-D molecular alloy clusters of the type [MM'Fe(CO)] (M, M' = Cu, Ag, Au; M ≠ M') have been prepared through the reactions of [CuFe(CO)], [AgFe(CO)] or [MFe(CO)] (M = Cu, Ag) with M'(I) salts (M' = Cu, Ag, Au). Their formation involves a combination of oxidation, condensation, and substitution reactions. The total structures of several [MM'Fe(CO)] clusters with different compositions have been determined by means of single crystal X-ray diffraction (SC-XRD) and their nature in solution elucidated by electron spray ionization mass spectrometry (ESI-MS) and IR and UV-visible spectroscopy.

Redox active Ni-Pd carbonyl alloy nanoclusters: syntheses, molecular structures and electrochemistry of [NiPd(CO)] (x = 0.62), [NiPd(CO)] (x = 0.09) and [NiPd(CO)] (x = 0.27).

A redox active Ni-Pd alloy nanocluster [NiPd(CO)] (x = 0.62) ([1]) was obtained from the redox condensation of [NBu][Ni(CO)] with 0.7-0.

Rh-Sb Nanoclusters: Synthesis, Structure, and Electrochemical Studies of the Atomically Precise [RhSb(CO)] and [RhSb(CO)] Carbonyl Compounds.

The reactivity of [Rh(CO)] with SbCl has been deeply investigated with the aim of finding a new approach to prepare atomically precise metalloid clusters. In particular, by varying the stoichiometric ratios, the reaction atmosphere (carbon monoxide or nitrogen), the solvent, and by working at room temperature and low pressure, we were able to prepare two large carbonyl clusters of nanometer size, namely, [RhSb(CO)] and [RhSb(CO)]. A third large species composed of 28 metal atoms was isolated, but its exact formulation in terms of metal stoichiometry could not be incontrovertibly confirmed.

Thermal Growth of Au-Fe Heterometallic Carbonyl Clusters Containing N-Heterocyclic Carbene and Phosphine Ligands.

The thermal reactions of [NEt][Fe(CO)(AuNHC)] [NHC = IMes ([NEt][]) or IPr ([NEt][]); IMes = CNH(CHMe); IPr = CNH(CHPr)], Fe(CO)(AuNHC) [NHC = IMes () or IPr ()], Fe(CO)(AuIMes)(AuIPr) (), and Fe(CO)(AuNHC)(AuPPh) [NHC = IMes () or IPr ()] were investigated in different solvents [CHCl, CHCN, dimethylformamide, and dimethyl sulfoxide (dmso)] and at different temperatures (50-160 °C) in an attempt to obtain higher-nuclearity clusters. and completely decomposed in refluxing CHCl, resulting in [Fe(CO)(AuNHC)] [NHC = IMes () or IPr ()]. Traces of [Fe(CO)(CCH)] () were obtained as a side product.

Cluster Core Isomerism Induced by Crystal Packing Effects in the [HCoPdC(CO)] Molecular Nanocluster.

This article describes a rare case of cluster core isomerism in a large molecular organometallic nanocluster. In particular, two isomers of the [HCoPdC(CO)] nanocluster, referred as TP-Pd and Oh-Pd, have been structurally characterized by single-crystal X-ray crystallography as their [NMe(CHPh)][HCoPdC(CO)]·CHCl (ca. 1:1 TP-Pd and Oh-Pd mixture), [NMe(CHPh)][HCoPdC(CO)]·2CHCl (mainly TP-Pd), [NEt(CHPh)][HCoPdC(CO)]·CHCl (mainly TP-Pd), [MePPh][HCoPdC(CO)]·2.

Polymerization Isomerism in [{MFe(CO)} ] (M = Cu, Ag, Au; n = 3, 4) Molecular Clusters Supported by Metallophilic Interactions.

Triangular clusters [{MFe(CO)}] (M = Cu, 4; Ag, 5; Au, 6) were selectively obtained by heating Fe(CO)(MIMes) (M = Cu, 1; Ag, 2; Au, 3; IMes = CNH(CHMe)). 1-3 were synthesized by reacting Na[Fe(CO)]·2thf with 2 equiv of M(IMes)Cl. As previously described, the direct reactions of Na[Fe(CO)]·2thf with one equivalent of M(I) salts resulted in the triangular cluster [{CuFe(CO)}] for Cu, whereas the square clusters [{MFe(CO)}] were formed for Ag and Au.

From Mononuclear Complexes to Molecular Nanoparticles: The Buildup of Atomically Precise Heterometallic Rhodium Carbonyl Nanoclusters.

Chemical research in synthesizing metal nanoparticles has been a major topic in the last two decades, as nanoparticles can be of great interest in many fields such as biology, catalysis, and nanotechnology. However, as their chemical and physical properties are size-dependent, the reliable preparation of nanoparticles at a molecular level is highly desirable. Despite the remarkable advances in recent years in the preparation of thiolate- or p-MBA or PA-protected gold and silver nanoclusters ( p-MBA = p-mercaptobenzoic acid; PA = phenylalkynyl), as well as the large palladium clusters protected by carbonyl and phosphine ligands that initially dominated the field, the synthesis of monodispersed and atomically precise nanoparticles still represents a great challenge for chemists.

Insertion of germanium atoms in high-nuclearity rhodium carbonyl compounds: synthesis, characterization and preliminary biological activity of the heterometallic [RhGe(CO)], [RhGe(CO)] and [RhGe(CO)] clusters.

The reaction of the [Rh7(CO)16]3- cluster anion with Ge2+ salts, in different stoichiometric ratios and under different atmospheres, leads to the formation of new heterometallic Rh-Ge clusters, representing the first known examples of Rh carbonyl compounds containing interstitial germanium atoms. More specifically, under N2 the reaction progressively affords the new [Rh13Ge(CO)25]3- and [Rh14Ge2(CO)30]2- clusters in good yields, with the Ge atoms located in cubic and square-anti-prismatic cavities, respectively. However, under a CO atmosphere, the [Rh13Ge(CO)25]3- derivative undergoes a significant structural and chemical rearrangement giving the new compound, [Rh12Ge(CO)27]4-, where Ge is hosted in an icosahedral metal cage.

Synthesis of [Pt(CO)(dppm)] and [Pt(CO)(dppm)] Heteroleptic Chini-type Platinum Clusters by the Oxidative Oligomerization of [Pt(CO)(dppm)].

The reactions of [Pt(CO)] with CH(PPh) (dppm), CH═C(PPh) (P^P), and Fe(CHPPh) (dppf) proceed via nonredox substitution and result in the heteroleptic Chini-type clusters [Pt(CO)(dppm)], [Pt(CO)(P^P)], and [Pt(CO)(dppf)], respectively. Conversely, the reactions of [Pt(CO)] with PhP(CH)PPh (dppb) and PhPC≡CPPh (dppa) can be described as redox fragmentation that afford the neutral complexes Pt(dppb), Pt(CO)(dppa), and Pt(CO)(PPh)(C≡CPPh)(dppa). The oxidation of [Pt(CO)(dppm)] results in its oligomerization to yield the larger heteroleptic Chini-type clusters [Pt(CO)(dppm)], [Pt(CO)(dppm)], and [Pt(CO)(dppm)] (for the latter there is only IR spectroscopic evidence).

Water soluble derivatives of platinum carbonyl Chini clusters: synthesis, molecular structures and cytotoxicity of [Pt(CO)(PTA)] and [Pt(CO)(PTA)] .

The reactions of [Pt3n(CO)6n]2- (n = 2-5) homoleptic Chini-type clusters with increasing amounts of 1,3,5-triaza-7-phosphaadamantane (PTA) result in the stepwise substitution of one terminal CO ligand per Pt3 triangular unit up to the formation of [Pt3n(CO)5n(PTA)n]2- (n = 2-5). Competition between the nonredox substitution with retention of the nuclearity and the redox fragmentation to afford lower nuclearity heteroleptic Chini-type clusters is observed as a function of the amount of PTA and the nuclearity of the starting cluster. Because of this, [Pt12(CO)20(PTA)4]2- and [Pt15(CO)25(PTA)5]2- are more conveniently obtained via the oxidation of [Pt9(CO)15(PTA)3]2-.

Molecular Nickel Phosphide Carbonyl Nanoclusters: Synthesis, Structure, and Electrochemistry of [NiP(CO)] and [HNiP(CO)] (n = 4 and 5).

The reaction of [NEt][Ni(CO)] in thf with 0.5 equiv of PCl affords the monophosphide [NiP(CO)] that in turn further reacts with PCl resulting in the tetra-phosphide carbonyl cluster [HNiP(CO)]. Alternatively, the latter can be obtained from the reaction of [NEt][Ni(CO)] in thf with 0.