Three- and Five-Membered Anionic Chains of Pnictogenylboranes.

An unprecedented family of three- and five-membered substituted anionic derivatives of parent pnictogenylboranes is herein reported. Reacting various combinations of the pnictogenylboranes H2 E'-BH2 -NMe3 (E'=P, As) with pnictogen-based nucleophiles MER1R2 (E=P, As; R1=H, R2=t Bu; R1=R2=Ph; M=Na, K) allows for the isolation of the unsymmetrical products [Na(18-crown-6)][H2 E'-BH2 -EHt Bu] (3: E=E'=P; 4: E=E'=As; 5: E=As, E'=P) and [M(C)][H2 E'-BH2 -EPh2 ] (7: E=E'=P, M=Na, C=18-crown-6; 8: E=E'=As; M=K, C=[2.2.2]cryptand; 9: E=P, E'=As, M=Na, C=[2.2.2]cryptand; 10: E=As, E'=P, M=K, C=[2.2.2]cryptand). [Na(18-crown-6)][H2 As-BH2 -t BuPH-BH3 ] (6) is only accessible by a different pathway, using t BuPH2 , BH3 ⋅ SMe2 and NaNH2 as starting materials. Additionally, the synthesis of symmetrical diphenyl-substituted compounds [M(18-crown-6)][Ph2 E-BH2 -EPh2 ] (11: E=P, M=Na; 12: E=As, M=K) is reported which can be regarded as isostructural inorganic, negatively charged analogs of dppm (1,1-bis(diphenylphosphino)methane) and dpam (1,1-bis(diphenylarsino)methane). Furthermore, an elongation of the pnictogen boron backbone in compounds 3, 7 and 9' (similar compound to 9, stabilized however by 18-crown-6), is attainable by reacting them with the pnictogenylboranes H2 E'-BH2 -NMe3 leading to corresponding five-membered chain-like compounds [Na(18-crown-6)][H2 E-BH2 -R1R2P-BH2 -E'H2 ] (E=E'=P, R1=H, R2=t Bu (13); E=E'=P, R1=R2=Ph (14); E=E'=As, R1=R2=Ph (15); E=P, E'=As, R1=R2=Ph (16)). Finally, the thermodynamics of the reaction pathways were evaluated by quantum chemical computations.

Versatile Coordination of AgI and CuI Ions towards cyclo-As5 Ligands.

The reactions of the cyclo-As5 complex [Cp*Fe(η5 -As5 )] (B) with the AgI and CuI salts of the weakly coordinating anion (WCA) [FAl{OC6 F10 (C6 F5 )}3 ]- ([FAl]- ) are studied. These reactions allow the synthesis of the mononuclear complexes [M(η5 : η2 -B)2 ][FAl] (M=Ag (1), Cu (2)) when a ratio of B/M(FAl) 2 : 1 is used. Compound 1 shows an unusual disorder of the central AgI cation between two π-coordinating cyclo-As5 ligands, which is absent in 2 pointing to a weak interaction of the Ag center towards the cyclo-As5 ligands in B. When the ratio of B/Ag(FAl) is changed to 3 : 1 or 1 : 1, the respective coordination compounds [Ag(η2 -B)3 ][FAl] (3) and [Ag2 (η2 : η2 -B)2 ][FAl]2 (4) are accessible. The coordination modes of the cyclo-As5 units in 1, 3 and 4 are all different, reflecting the adaptive coordination behavior of B towards AgI ions. The optimized geometries in the gas phase of 1-4 are determined by DFT calculations to support the bonding situation observed in their solid-state structures.

The Potential of the Diarsene Complex [(C5 H5 )2 Mo2 (CO)4 (µ,η2 -As2 )] as a Connector Between Silver Ions.

The reaction of the organometallic diarsene complex [Cp2 Mo2 (CO)4 (µ,η2 -As2 )] (B) (Cp = C5 H5 ) with Ag[FAl{OC6 F10 (C6 F5 )}3 ] (Ag[FAl]) and Ag[Al{OC(CF3 )3 }4 ] (Ag[TEF]), respectively, yields three unprecedented supramolecular assemblies [(η2 -B)4 Ag2 ][FAl]2 (4), [(µ,η1 :η2 -B)3 (η2 -B)2 Ag3 ][TEF]3 (5) and [(µ,η1 :η2 -B)4 Ag3 ][TEF]3 (6). These products are only composed of the complexes B and AgI . Moreover, compounds 5 and 6 are the only supramolecular assemblies featuring B as a linking unit, and the first examples of [AgI ]3 units stabilized by organometallic bichelating ligands. According to DFT calculations, complex B coordinates to metal centers through both the As lone pair and the As-As σ-bond thus showing this unique feature of this diarsene ligand.

Adaptive Coordination-Driven Supramolecular Syntheses toward New Polymetallic Cu(I) Luminescent Assemblies.

A thermally activated delayed fluorescence (TADF) tetrametallic Cu(I) metallacycle A behaves as a conformationally adaptive preorganized precursor to afford, through straightforward and rational coordination-driven supramolecular processes, a variety of room-temperature solid-state luminescent polymetallic assemblies. Reacting various cyano-based building blocks with A, a homometallic Cu(I) 1D-helical coordination polymer C and Cu8M discrete circular heterobimetallic assemblies DM (M = Ni, Pd, Pt) are obtained. Their luminescence behaviors are studied, revealing notably the crucial impact of the spin-orbit coupling offered by the central M metal center on the photophysical properties of the heterobimetallic DM derivatives.

Organometallic-Organic Hybrid Polymers Assembled from Pentaphosphaferrocene, Bipyridyl Linkers, and CuI Ions.

A multicomponent approach of the P n ligand complex [Cp*Fe(η5-P5)] (1: Cp* = η5-C5Me5) with the ditopic organic linkers 4,4'-bipyridine (2) or trans-1,2-di(pyridine-4-yl)ethene (3) in the presence of CuI salts of the anions [BF4]- and [PF6]- or the coordinating anion Br-, leads to the formation of four novel organometallic-organic hybrid polymers: the cationic 1D polymeric compounds [Cu4{Cp*Fe(µ3,η5:1:1-P5)}2(µ,η1:1-C10H8N2)4(CH3CN)4] n [BF4]4n (4) and [Cu4{Cp*Fe(µ3,η5:1:1-P5)}2(µ,η1:1-C10H8N2)4(CH3CN)4] n [PF6]4n (5) as well as the unique neutral threefold 2D → 2D interpenetrated networks [Cu2Cl2{Cp*Fe(µ3,η5:1:1-P5)}(µ,η1:1-C12H10N2)] n (6) and [Cu2Br2{Cp*Fe(µ3,η5:1:1-P5)}(µ,η1:1-C10H8N2)] n (7).

Preorganized AgI Bimetallic Precursor with Labile Diphosphorus Ligands for a Programmed Synthesis of Organometallic-Organic Hybrid Polymers.

An AgI dimer capped with labile organometallic diphosphorus ligands [Cp2 Mo2 (CO)4 (η2 -P2 )] (Cp=C5 H5 ) acts as a highly pre-organized molecular precursor to direct the construction of 1D or 2D, and 3D organometallic-organic hybrid coordination polymers upon reaction with ditopic pyridine-based linkers. The formation of the supramolecular aggregates can be controlled by the stoichiometry of the organic molecules, and the mechanism is supported by DFT calculations.

The Diphosphorus Complex [Cp2Mo2(CO)4(η2-P2)] as a Building Block for the Synthesis of Mixed-Hybrid Coordination Polymers.

The three-component reaction of the tetrahedral diphosphorus complex [Cp2Mo2(CO)4(η2-P2)] (1), with Ag[BF4] (2) in the presence of 2,2'-bipyrimidine (3) leads to the formation of the two novel two-dimensional networks 4 and 5. Compound 4 is a new two-dimensional organometallic-organic hybrid polymer, while derivative 5 represents a unique two-dimensional organometallic-inorganic-organic hybrid polymer. These results show the possibility of synthesizing a new class of coordination polymers, which could not be obtained from two-component reactions with organic molecules in addition of metal ions.

Organometallic polyphosphorus and -arsenic ligands as linkers between pre-assembled linear Cu(I) fragments.

A simple and straightforward synthesis of a new linear trinuclear Cu(I) cluster with polyphosphine ligands is presented. The reaction of this pre-organized Cu3 precursor with En ligand complexes (E = P, As; n = 2, 5) affords discrete complexes exhibiting end-on η(1)-coordination of the E2 ligands or one-dimensional coordination polymers featuring σ-1,3-bridging E5 rings, respectively.