The Potential of Molybdenum Complexes Bearing Unsubstituted Heterodiatomic Group 15 Elements as Linkers in Supramolecular Chemistry

Potential of Mixed Dipnictogen Molybdenum Complexes in the Self-Assembly of Thallium Coordination Compounds

The coordination chemistry of the homo- and heterodipnictogen tetrahedrane complexes [{CpMo(CO)2}2(μ,η2:2-EE')] (E, E' = P, As, Sb) (A-F) toward Tl[BArF24] ([BArF24]- = [B(3,5-C6H3(CF3)2)4]-) was studied. Controlled by the used tetrahedranes A-F, and thus depending on the respective pnictogen atoms, the monomers [Tl(η2-A)][BArF24] ([A]Tl) and [Tl(η2-B)][BArF24] ([B]Tl), the double substituted [Tl(η1-C)2][BArF24] ([C]2Tl) or the even higher aggregated compounds [Tl2(η2-D)3(μ,η2:1-D)(μ,η1:1-D)][BArF24]2 ([D]5Tl2), [Tl2(η2-E)2(μ,η2:1-E)3] [BArF24]2 ([E]5Tl2) and [Tl2(η2-F)3(μ,η2:1-F)3][BArF24]2 ([F]6Tl2) were obtained. Utilization of [BArF24]- promises additional stabilization of TlI via η6-coordination of two of its aryl rings as found in compounds [A]Tl, [B]Tl and [C]2Tl. Within the series of reactivity of A-F, the heavier congeners D, E and F tend to form larger aggregates in which σ(E-E') bond contributions to the coordination behavior were observed. Interatomic distances suggest the presence of Tl···Tl interactions in [E]5Tl2 and [F]6Tl2. The features of the respective coordination compounds were studied in the solid-state as well as in solution. For the latter at least a partial dissociation of the assemblies in solution was indicated. The isolated solid-state aggregates are the first examples of heterodipnictogen units as ligands in self-assembled TlI-based coordination compounds.

Supramolecular compounds assembled from the heteroleptic tetrahedral complex [{CpMo(CO)2}2(μ,η2-AsSb)] and metal salts

The reaction of the tetrahedral complex [{CpMo(CO)2}2(μ,η2-AsSb)] with CuI and AgI salts is presented which gives unprecedented neutral and cationic supramolecular aggregates featuring mixed As/Sb-donor molecules as ligands/linkers between metal ions.

Cu(I) Complexes Comprising tetrahedral Mo2 E2 or Mo2 PE units (E=P, As, Sb) as Chelating Ligands

Novel isomorphous tetranuclear complexes, [(dppf)Cu(μ3 ,η2 : 2 : 2 -E2 {CpMo(CO)2 }2 ]BF4 [E=P (1), As (4), Sb (5), (dppf=1,1'-bis-(diphenylphosphino)-ferrocene)] and [(dppf)Cu(μ3 ,η2 : 2 : 2 -PE{CpMo(CO)2 }2 ]BF4 [E=As (2), Sb(3)] were synthesized from the reactions between [(dppf)Cu(MeCN)2 ][BF4 ] and tetrahedral molybdenum complexes containing unsubstituted homo- and hetero-diatomic group-15 elements [(μ,η2 : 2 -E2 {CpMo(CO)2 }2 ] [E=P (A), As (D), Sb (E)] and [(μ,η2 : 2 -PE{CpMo(CO)2 }2 ] [E=As (B), Sb (C)], respectively. In all these products, the {Mo2 E2 } or {Mo2 PE} moieties coordinate the Cu(I) center via a rare side-on η2 -coordination mode. The X-ray structure analyses of [(dppf)Cu(μ3 ,η2 : 2 : 1 -PSb{CpMo(CO)2 }2 ][BF4 ] demonstrate, for the first time, the utilization of an η1 -coordination mode for the ligand complex C to coordinate to the Cu(I) center. All the products were characterized by X-ray crystallography, NMR and IR spectroscopy, mass spectrometry and elemental analysis. Electrochemical studies also revealed the formation of 1-5, and, further, to understand the structure and bonding of the products, theoretical calculations using density functional theory (DFT) were conducted.

Novel synthetic route towards heteroleptic pnictogen-rich organometallic-inorganic coordination compounds

The reaction of the Ag(I) dimer [Ag2(η2-A)2(μ,η1:η1-A)2][TEF]2 (A = [{CpMo(CO)2}2(μ,η2-P2)]) possessing labile η2-coordinated P2 ligands with the organometallic dipnictogen compounds [{CpMo(CO)2}2(μ,η2-EE')] (E = E' = As, Sb; E = P, E' = As, Sb) represents a facile synthetic route towards unprecedented heteroleptic pnictogen-rich supramolecular complexes. This method can also be extended to the analogous Cu(I) dimer and is studied by DFT computations.

Structural, Spectroscopic, and Computational Analysis of Heterometallic Thorium Phosphinidiide Complexes

To synthesize complexes with thorium-phosphorus multiple-bond character, reactions of (C₅Me₅)₂Th[P(H)Mes]₂ with monovalent alkali-metal bases, MN(SiMe₃)₂, as well as CuMes, have been investigated. The results with MN(SiMe₃)₂ are phosphinidiide complexes of the form {(C₅Me₅)₂Th[μ₂-P(Mes)][μ₂-P(H)Mes]M(L)_n}₂ (M = Na, n = 0; M = K, L = THF, n = 1; M = Rb, L = THF, n = 1; M = Cs, L = Et₂O, n = 1). With CuMes, the product is a Th₂Cu₃P₅ heterometallic structure, {(C₅Me₅)₂Th[(μ₂-P(H)Mes)P(Mes)]Cu}₂Cu[μ₂-P(H)Mes]. All complexes have been characterized using heteronuclear NMR and IR spectroscopy, density functional theory calculations, and their solid-state structure identified by X-ray crystallography. We also report the structure of {(C₅Me₅)₂Th[(μ₂-As(H)Mes)As(Mes)]Cu}₂Cu[μ₂-As(H)Mes] obtained from (C₅Me₅)₂Th[As(H)Mes]₂ with CuMes.

Discrete and polymeric organometallic-organic assemblies based on the diarsene complex [(Cp)2Mo2(CO)4(μ,η2-As2)], AgPF6 and N-donor organic molecules

The first mixed-ligand self-assembly reactions of the diarsene complex [Cp₂Mo₂(CO)₄(μ,η²-As₂)] and N-donor organic molecules in the presence of AgPF₆ allow for the synthesis of two discrete and four polymeric supramolecular aggregates.

Linking of CuI Units by Tetrahedral Mo2 E2 Complexes (E=P, As)

The reaction of [Cp2 Mo2 (CO)4 (μ,η2:2 -E2 )] (A: E=P, B: E=As, Cp=C5 H5 ) with the WCA-containing CuI salts ([Cu(CH3 CN)4 ][Al{OC(CF3 )3 }4 ] (CuTEF, C), [Cu(CH3 CN)4 ][BF4 ] (D) and [Cu(CH3 CN)3.5 ][FAl{OC6 F10 (C6 F5 )}3 ] (CuFAl, E)) affords seven unprecedented coordination compounds. Depending on the E2 ligand complex, the counter anion of the copper salt and the stoichiometry, four dinuclear copper dimers and three trinuclear copper compounds are accessible. The latter complexes reveal first linear Cu3 arrays linked by E2 units (E=P, As) coordinated in an η2:1:1 coordination mode. All compounds were characterized by X-ray crystallography, NMR and IR spectroscopy, mass spectrometry and elemental analysis. To define the nature of the Cu⋅⋅⋅Cu⋅⋅⋅Cu interactions, DFT calculations were performed.

Metal carbonyl cluster-based coordination polymers: diverse syntheses, versatile network structures, and special properties

This highlight surveys recent progress in groups 6–10 metal carbonyl cluster-based coordination polymers, focusing on diverse synthetic strategies, versatile structures, structural transformations, and semiconducting as well as magnetic properties.