Synthesis and Reactivity of a Cyclooctatetraene-Like Polyphosphorus Ligand Complex [Cyclo-P ].

The thermolysis of Cp'''Ta(CO) with white phosphorus (P ) gives access to [{Cp'''Ta} (μ,η -P )] (A), representing the first complex containing a cyclooctatetraene-like (COT) cyclo-P ligand. While ring sizes of n >6 have remained elusive for cyclo-P structural motifs, the choice of the transition metal, co-ligand and reaction conditions allowed the isolation of A. Reactivity investigations reveal its versatile coordination behaviour as well as its redox properties.

Across the Dimensions: A Three-Component Self-Assembly of Pentaphosphaferrocene-based Coordination Polymers.

Pentaphosphaferrocenes [Cp Fe(η -P )] (Cp*=η -C Me ) (A), Cp''=η -C H tBu -1,3 (B)) are excellent building blocks for polymeric assemblies in supramolecular chemistry in combination with coinage metal salts of weakly coordinating anions such as AgSbF . Adding rigid aromatic dinitriles ortho/meta/para-(NC) C H in a one-pot reaction between [Cp Fe(η -P )] and AgSbF leads to various coordination polymers (CPs) by a three-component self-assembly. The sterical demand of the differently substituted cyclopentadiene ligands as well as the rigid constitution of the isomeric dinitriles (NC) C H play a key role in the formation of the isolated CPs.

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 H E'-BH -NMe (E'=P, As) with pnictogen-based nucleophiles MER1R2 (E=P, As; R1=H, R2= Bu; R1=R2=Ph; M=Na, K) allows for the isolation of the unsymmetrical products [Na(18-crown-6)][H E'-BH -EH Bu] (3: E=E'=P; 4: E=E'=As; 5: E=As, E'=P) and [M(C)][H E'-BH -EPh ] (7: E=E'=P, M=Na, C=18-crown-6; 8: E=E'=As; M=K, C=[2.2.

Structural Chemistry of Giant Metal Based Supramolecules.

The review presents a bird-eye view on the state of research in the field of giant nonbiological discrete metal complexes and ions of nanometer size, which are structurally characterized by means of single-crystal X-ray diffraction, using the crystal structure as a common key feature. The discussion is focused on the main structural features of the metal clusters, the clusters containing compact metal oxide/hydroxide/chalcogenide core, ligand-based metal-organic cages, and supramolecules as well as on the aspects related to the packing of the molecules or ions in the crystal and the methodological aspects of the single-crystal neutron and X-ray diffraction of these compounds.

Insertion of Phosphenium Ions into a Bicyclo[1.1.0]Tetraphosphabutane Iron Complex.

By reacting [{Cp‴Fe(CO)}(µ,η-P)] () with in situ generated phosphenium ions [PhP][A] ([A] = [OTf] = [OSCF], [PF]), a mixture of two main products of the composition [{Cp‴Fe(CO)}(µ,η-P(CH))][PF] ( and ) could be identified by extensive P NMR spectroscopic studies at 193 K. Compound was also characterized by X-ray diffraction analysis, showing the rarely observed bicyclo[2.1.

Versatile Coordination of Ag and Cu Ions towards cyclo-As Ligands.

The reactions of the cyclo-As complex [Cp*Fe(η -As )] (B) with the Ag and Cu salts of the weakly coordinating anion (WCA) [FAl{OC F (C F )} ] ([FAl] ) are studied. These reactions allow the synthesis of the mononuclear complexes [M(η  : η -B) ][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 Ag cation between two π-coordinating cyclo-As ligands, which is absent in 2 pointing to a weak interaction of the Ag center towards the cyclo-As ligands in B.

Au-Containing Coordination Polymers Based on Polyphosphorus Ligand Complexes.

Whereas the self-assembly of pentaphosphaferrocenes [CpFe(η-P)] (Cp = Cp*, Cp, and Cp) with Cu and Ag salts has been well-studied in the past, the coordination chemistry toward Au complexes has been left untouched so far. Herein, the results of the self-assembly processes of [CpFe(η-P)] with Au salts of different anions (GaCl, SbF, and Al(OC(CF)) (TEF)) are reported. Next to a variety of molecular coordination products, the first coordination polymers based on polyphosphorus ligand complexes and Au salts are also obtained.

Three-Component Self-Assembly Changes its Course: A Leap from Simple Polymers to 3D Networks of Spherical Host-Guest Assemblies.

One-pot self-assembly reactions of the polyphosphorus complex [Cp*Fe(η -P )] (A), a coinage metal salt AgSbF , and flexible aliphatic dinitriles NC(CH ) CN (x=1-10) yield 1D, 2D, and 3D coordination polymers. The seven-membered backbone of the dinitrile was experimentally found as the borderline for the self-assembly system furnishing products of different kinds. At x<7, various rather simple polymers are exclusively formed possessing either 0D or 1D Ag/A structural motifs connected by dinitrile spacers, while at x≥7, the self-assembly switches to unprecedented extraordinary 3D networks of nano-sized host-guest assemblies (SbF )@[(A) Ag ] (x=7) or (A)@[(A) Ag ] (x=8-10) linked by dinitriles.

The Missing Parent Compound [(C H )Fe(η -P )]: Synthesis, Characterization, Coordination Behavior and Encapsulation.

The so far missing parent compound of the large family of pentaphosphaferrocenes [CpFe(η -P )] (1 b) was synthesized by the thermolysis of [CpFe(CO) ] with P using the very high-boiling solvent diisopropylbenzene. It was comprehensively characterized by, inter alia, NMR spectroscopy, single crystal X-ray structure analysis, cyclic voltammetry and DFT computations. Moreover, its coordination behavior towards Cu halides was explored, revealing the unprecedented 2D polymeric networks [{CpFe(η -P )}Cu (μ-X) ] (2 a: X=Cl, 2 b: X=Br) and [{CpFe(η -P )}Cu(μ-I)] (3) and even the first cyclo-P -containing 3D coordination polymer [{CpFe(η -P )}Cu(μ-I)] (4).

Iodination of cyclo-E -Complexes (E=P, As).

In a high-yield one-pot synthesis, the reactions of [Cp*M(η -P )] (M=Fe (1), Ru (2)) with I resulted in the selective formation of [Cp*MP I ] salts (3, 4). The products comprise unprecedented all-cis tripodal triphosphino-cyclotriphosphine ligands. The iodination of [Cp*Fe(η -As )] (6) gave, in addition to [Fe(CH CN) ] salts of the rare [As I ] (in 7) and [As I ] (in 8) anions, the first di-cationic Fe-As triple decker complex [(Cp*Fe) (μ,η -As )][As I ] (9).

Metal-Deficient Supramolecule Based on a Fivefold-Symmetric Building Block.

An unprecedented cationic supramolecule [(Cp''Fe(η -P )) {CuNCMe} ] 2.66 nm in diameter was selectively isolated as a salt of the weakly coordinating anion [Al{OC(CF ) } ] for the first time and characterized by X-ray structure analysis, PXRD, NMR spectroscopy, and mass spectrometry. Its metal-deficient core contains the lowest possible number of Cu atoms to connect 12 pentaphosphaferrocene units, providing a supramolecule with fullerene topology which, topologically, also represents the simplest homologue in the family of metal-deficient pentaphosphaferrocene-based supramolecules [{Cp Fe(η -P )} (CuX) ].

From nano-balls to nano-bowls.

Pentaphosphaferrocene [Cp*Fe(η-P)] in combination with Cu(i) halides is capable of a template-directed synthesis of fullerene-like spheres. Herein, we present the use of a triple decker complex as template that leads to the formation of unprecedented 'nano-bowls'. These spherical domes resemble the truncated fullerenes -C and represent a novel spherical arrangement in the chemistry of spherical molecules.

The Lewis-Base-Stabilized Diphenyl-Substituted Arsanylborane: A Versatile Building Block for Arsanylborane Oligomers.

The synthesis and properties of the diphenyl-substituted arsanylborane Ph AsBH SMe (1) and Ph AsBH NMe (2) stabilized by a Lewis base (LB) were reported. These compounds were obtained by reaction of KAsPh with IBH -LB (LB=SMe , NMe ). Compounds 1 and 2 were used as starting materials for oligomeric/ polymeric arsinoboranes.

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

A multicomponent approach of the P ligand complex [Cp*Fe(η-P)] (: Cp* = η-CMe) with the ditopic organic linkers 4,4'-bipyridine () or -1,2-di(pyridine-4-yl)ethene () in the presence of Cu salts of the anions [BF] and [PF] or the coordinating anion Br, leads to the formation of four novel organometallic-organic hybrid polymers: the cationic 1D polymeric compounds [Cu{Cp*Fe(µ,η-P)}(µ,η-CHN)(CHCN)] [BF] () and [Cu{Cp*Fe(µ,η-P)}(µ,η-CHN)(CHCN)] [PF] () as well as the unique neutral threefold 2D → 2D interpenetrated networks [CuCl{Cp*Fe(µ,η-P)}(µ,η-CHN)] () and [CuBr{Cp*Fe(µ,η-P)}(µ,η-CHN)] ().

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

An Ag dimer capped with labile organometallic diphosphorus ligands [Cp Mo (CO) (η -P )] (Cp=C H ) 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.

Transfer Reagent for Bonding Isomers of Iron Complexes.

The cothermolysis of As and [Cp″Zr(CO)] (Cp″ = η-CHtBu) results in the formation of [Cp″Zr(η-As)] (1) in high yields and the arsenic-rich complex [(Cp″Zr)(Cp″Zr)(μ,η-As)] (2) as a minor product. In contrast to yellow arsenic, 1 is a light-stable, weighable and storable arsenic source for subsequent reactions. The transfer reaction of 1 with [Cp‴Fe(μ-Br)] (Cp‴ = η-CHtBu) yields the unprecedented bond isomeric complexes [(Cp‴Fe)(μ,η-As)] (3a) and [(Cp‴Fe)(μ,η-cyclo-As)] (3b).

An Icosidodecahedral Supramolecule Based on Pentaphosphaferrocene: From a Disordered Average Structure to Individual Isomers.

Pentaphosphaferrocenes [Cp Fe(η -P )] (1) and Cu halides are excellent building blocks for the formation of discrete supramolecules. Herein, we demonstrate the potential of Cu(CF SO ) for the construction of the novel 2D polymer [{Cp*Fe(μ ,η -P )}{Cu(CF SO )}] (2) and the unprecedented nanosphere (CH Cl ) @[{Cp Fe(η -P )} {Cu(CF SO )} ] (3). The supramolecule 3 has a unique scaffold beyond the fullerene topology, with 20 copper atoms statistically distributed over the 30 vertices of an icosidodecahedron.

Cationic Chains of Parent Arsanylboranes and Substituted Phosphanylboranes.

The substituted monomeric phosphanylboranes Ph P-BH ⋅NMe (1) and tBuHP-BH ⋅NMe (2) have been used for the synthesis of cationic chain compounds built up by R P-BH units. With a simple synthesis route, the highly stable cations [Me N⋅H B-PR R -BH ⋅NMe ] (1 a, 2 a) and [Me N⋅H B-PR R -BH -PR R -BH ⋅NMe ] (1 b, 2 b) (R =R =Ph; R =H, R =tBu) are obtained as iodide (I ) salts. The reaction of H As-BH ⋅NMe (3) with IBH ⋅SMe leads to [Me N⋅H B-AsH -BH -AsH -BH ⋅NMe ][I] (3 a), the longest so far known arsanylborane chain.

Arsenic-Rich Polyarsenides Stabilized by Cp*Fe Fragments.

The redox chemistry of [Cp*Fe(η -As )] (1, Cp*=η -C Me ) has been investigated by cyclic voltammetry, revealing a redox behavior similar to that of its lighter congener [Cp*Fe(η -P )]. However, the subsequent chemical reduction of 1 by KH led to the formation of a mixture of novel As scaffolds with n up to 18 that are stabilized only by [Cp*Fe] fragments. These include the arsenic-poor triple-decker complex [K(dme) ][{Cp*Fe(μ,η -As )} ] (2) and the arsenic-rich complexes [K(dme) ] [(Cp*Fe) (μ,η -As )] (3), [K(dme) ] [(Cp*Fe) (μ,η -As )] (4), and [K(dme) ] [(Cp*Fe) (μ ,η -As )] (5).

Homoleptic Phosphaalkyne Complexes of Silver(I).

By employing silver salts with a weakly coordinating anion Ag[A] ([A]=[FAl{OC F } ], [Al{OC(CF ) } ]), two phosphaalkynes could be coordinated side-on to a bare silver(I) center to form the unprecedented homoleptic complexes [Ag(η -P≡CtBu) ][FAl{OC F } ] (1) and [Ag(η -P≡CtBu) ][Al{OC(CF ) } ] (2). DFT calculations show that the perpendicular arrangement in 1 is the minimum energy structure of the coordination of the two phosphaalkynes to a silver atom, whereas for 2 a unique square-planar coordination mode of the phosphaalkynes at Ag was found. Reactions with donor molecules yield the trigonally planar coordinated silver salts [((CH ) CO)Ag(η -P≡CtBu) ][FAl{OC F } ] (3) and [(C H ) Ag(η -P≡CtBu)][FAl{OC F } ] (4).

The First Coordination Polymers Based on 1,3-Diphosphaferrocenes and 1,1',2,3',4-Pentaphosphaferrocenes.

Phosphaferrocenes in combination with coinage metal salts proved to be excellent building blocks in supramolecular chemistry for the buildup of oligomeric and polymeric assemblies. The synthesis of a series of novel phosphaferrocenes containing the 1,3-PCPr and/or the 1,2,4-PCPr ligand is described herein. The self-assembly processes of the 1,3-diphospha-, 1,2,4-triphospha-, and 1,1',2,3',4-pentaphosphaferrocenes with Cu halides led to the formation of 1D or 2D polymers.

A cyclo-P6 Ligand Complex for the Formation of Planar 2D Layers.

The all-phosphorus analogue of benzene, stabilized as middle deck in triple-decker complexes, is a promising building block for the formation of graphene-like sheet structures. The reaction of [(CpMo)2 (μ,η(6) :η(6)-P6)] (1) with CuX (X=Br, I) leads to self-assembly into unprecedented 2D networks of [{(CpMo)2P6}(CuBr)4 ]n (2) and [{(CpMo)2 P6}(CuI)2]n (3). X-ray structural analyses show a unique deformation of the previously planar cyclo-P6 ligand.

Progress in Polyarsolyl Chemistry.

The synthesis of heteroatom analogues of the cyclopentadienyl anion Cp is a fascinating and challenging field of research. The replacement of methine moieties by phosphorus is well investigated for the synthesis of mono-, tri- and pentaphospholyl ligands. On the other hand, arsenic derivatives are rare and 1,2,4-triarsolyl and tetraarsolyl salts are unknown.

Versatile structures of group 13 metal halide complexes with 4,4'-bipy: from 1D coordination polymers to 2D and 3D metal-organic frameworks.

A systematic structural study of complexes formed by aluminium and gallium trihalides with 4,4'-bipyridine (bipy) in 2 : 1, 1 : 1, and 1 : 2 stoichiometric ratios has been performed. Molecular structures of 11 complexes in the solid state have been determined for the first time. Complexes of 2 : 1 composition are molecular, while complexes of 1 : 1 composition form metal-organic frameworks of different kinds: an ionic 3D network (three interpenetrated lvt nets for AlCl3bipy), an ionic 2D network for AlBr3bipy and GaBr3bipy and a 1D coordination polymer in the case of GaCl3bipy.

Topological Motifs in Cyanometallates: From Building Units to Three-Periodic Frameworks.

This review focuses on topological features of three-periodic (framework) p, d, and f metal cyano complexes or cyanometallates, i.e. coordination compounds, where CN(-) ligands play the main structure-forming role.