Homo- and heterobimetallic transition metal cluster derived from [Cp*Fe(η5-E5)] (E = P, As) - unprecedented structural motifs of the resulting polypnictogen ligands.

A general synthetic procedure to neutral homo- and heterobimetallic cage compounds exhibiting various structural motifs of the polypnictogen ligands starting from [Cp*Fe(η5-E5)] (E = P (1), As (2); Cp* = C5Me5) is reported. The impact of the implemented transition metal precursors {Cp'''M} (M = Cr, Mn, Fe, Ni; Cp''' = 1,2,4-tBu3C5H2) emphasises the variability of the isolated complexes exhibiting a broad variety of structural motifs of the pnictogen ligands. Spectroscopic, crystallographic, and theoretical investigations provide insight into the structure of the partially unprecedented polypnictogen ligands.

31P Nuclear Magnetic Resonance Spectroscopy as a Probe of Thorium-Phosphorus Bond Covalency: Correlating Phosphorus Chemical Shift to Metal-Phosphorus Bond Order.

We report the use of solution and solid-state 31P Nuclear Magnetic Resonance (NMR) spectroscopy combined with Density Functional Theory calculations to benchmark the covalency of actinide-phosphorus bonds, thus introducing 31P NMR spectroscopy to the investigation of molecular f-element chemical bond covalency. The 31P NMR data for [Th(PH2)(TrenTIPS)] (1, TrenTIPS = {N(CH2CH2NSiPri3)3}3-), [Th(PH)(TrenTIPS)][Na(12C4)2] (2, 12C4 = 12-crown-4 ether), [{Th(TrenTIPS)}2(µ-PH)] (3), and [{Th(TrenTIPS)}2(µ-P)][Na(12C4)2] (4) demonstrate a chemical shift anisotropy (CSA) ordering of (µ-P)3- > (═PH)2- > (µ-PH)2- > (-PH2)1- and for 4 the largest CSA for any bridging phosphido unit. The B3LYP functional with 50% Hartree-Fock mixing produced spin-orbit δiso values that closely match the experimental data, providing experimentally benchmarked quantification of the nature and extent of covalency in the Th-P linkages in 1-4 via Natural Bond Orbital and Natural Localized Molecular Orbital analyses. Shielding analysis revealed that the 31P δiso values are essentially only due to the nature of the Th-P bonds in 1-4, with largely invariant diamagnetic but variable paramagnetic and spin-orbit shieldings that reflect the Th-P bond multiplicities and s-orbital mediated transmission of spin-orbit effects from Th to P. This study has permitted correlation of Th-P δiso values to Mayer bond orders, revealing qualitative correlations generally, but which should be examined with respect to specific ancillary ligand families rather than generally to be quantitative, reflecting that 31P δiso values are a very sensitive reporter due to phosphorus being a soft donor that responds to the rest of the ligand field much more than stronger, harder donors like nitrogen.

Titanium-Catalyzed Polymerization of a Lewis Base-Stabilized Phosphinoborane.

The reaction of the Lewis base-stabilized phosphinoborane monomer tBuHPBH2 NMe3 (2 a) with catalytic amounts of bis(η5 :η1 -adamantylidenepentafulvene)titanium (1) provides a convenient new route to the polyphosphinoborane [tBuPH-BH2 ]n (3 a). This method offers access to high molar mass materials under mild conditions and with short reaction times (20 °C, 1 h in toluene). It represents an unprecedented example of a transition metal-mediated polymerization of a Lewis base-stabilized Group 13/15 compound. Preliminary studies of the substrate scope and a potential mechanism are reported.

Controlled introduction of functional groups at one P atom in [Cp*Fe(η5-P5)] and release of functionalised phosphines.

By salt metathesis reactions of the anionic complexes of the type [Cp*Fe(η4-P5R)]- (R = tBu (1a), Me (1b), -C[triple bond, length as m-dash]CPh (1c); Cp* = 1,2,3,4,5-pentamethylcyclopentadienyl) with organic electrophiles (XRFG; X = halogen; RFG = (CH2)3Br, (CH2)4Br, Me) a variety of organo-substituted polyphosphorus ligand complexes of the type [Cp*Fe(η4-P5RRFG)] (2) are obtained. Thereby, organic substituents with different functional groups (FG), such as halogens or nitriles, are introduced. In [Cp*Fe(η4-P5RR')] (2a: R = tBu, R' = (CH2)3Br), the bromine substituent can be easily substituted, leading to functionalized complexes [{Cp*Fe(η4-P5tBu)}(CH2)3{Cp*Fe(η4-P5Me)}] (4) and [Cp*Fe(η4-P5RR')] (5) (R = tBu, R' = (CH2)3PPh2) or by abstraction of a phosphine to the asymmetric substituted phosphine tBu(Bn)P(CH2)3Bn (6). The reaction of the dianionic species [K(dme)2]2[Cp*Fe(η4-P5)] (I') with bromo-nitriles leads to [Cp*Fe{η4-P5((CH2)3CN)2}] (7), allowing the introduction of two functional groups attached to one phosphorus atom. 7 reacts with ZnBr2 in a self-assembly reaction to form the supramolecular compound [Cp*Fe{η4-P5((CH2)3CN)2}ZnBr2]n (8).

Snapshots of sequential polyphosphide rearrangement upon metallatetrylene addition.

Insertion and functionalization of gallasilylenes [LPhSi-Ga(Cl)LBDI] (LPh = PhC(NtBu)2; LBDI = [{2,6-iPr2C6H3NCMe}2CH]) into the cyclo-E5 rings of [Cp*Fe(η5-E5)] (Cp* = η5-C5Me5; E = P, As) are reported. Reactions of [Cp*Fe(η5-E5)] with gallasilylene result in E-E/Si-Ga bond cleavage and the insertion of the silylene in the cyclo-E5 rings. [(LPhSi-Ga(Cl)LBDI){(η4-P5)FeCp*}], in which the Si atom binds to the bent cyclo-P5 ring, was identified as a reaction intermediate. The ring-expansion products are stable at room temperature, while isomerization occurred at higher temperature, and the silylene moiety further migrates to the Fe atom, forming the corresponding ring-construction isomers. Furthermore, reaction of [Cp*Fe(η5-As5)] with the heavier gallagermylene [LPhGe-Ga(Cl)LBDI] was also investigated. All the isolated complexes represent rare examples of mixed group 13/14 iron polypnictogenides, which could only be synthesized by taking advantage of the cooperativity of the gallatetrylenes featuring low-valent Si(ii) or Ge(ii) and Lewis acidic Ga(iii) units/entities.

Reactivity of [Cp''2 Zr(η1:1 -E4 )] (E=P, As) towards Nucleophiles.

The functionalization of the polypnictogen ligand complexes [Cp''2 Zr(η1:1 -E4 )] (E=P (1 a), As (1 b); Cp''=1,3-di-tertbutyl-cyclopentadienyl) is focused to modify the features of the polypnictogen unit to explore new synthetic pathways for further transformations. The reaction behavior of 1 towards main group nucleophiles is investigated. The reaction of 1 a with t BuLi leads to the ionic product Li[Cp''2 Zr(η1:1 -P4 t Bu)] (2) where an organic group is attached to a bridgehead phosphorus atom of the butterfly unit. Further reactions of 2 with quenching electrophilic reagents enable the introduction of other substituents. Moreover, a condensation of 2 to [(Cp''2 Zr)2 (µ,η1:1:1:1 -P8 t Bu2 )] (3), containing a novel P8 -unit, has been observed. The reaction of 1 with LiNMe2 and LiCH2 SiMe3 leads to a partial fragmentation of the E4 unit and the compounds [Cp''2 Zr(η2 -E3 Nu)] (Nu=NMe2 : E=P (6 a), As (6 b); Nu=CH2 SiMe3 : E=P (7 a), As (7 b)) are formed.

Transformation of the cyclo-P5 Middle Deck in [(Cp*Fe)(Cp'''Co)(µ,η5 :η4 -P5 )] upon Functionalization - A Comprehensive Study of Reactivity.

The heterobimetallic triple-decker complex [(Cp*Fe)(Cp'''Co)(µ,η5 : η4 -P5 )] (1) was functionalized by main group nucleophiles and subsequently electrophilically quenched or oxidized. Reacting 1 with group 14 nucleophiles revealed different organo-substituted P5 R middle-decks depending on the steric and electronic effects of the used alkali metal organyls (2: R=tBu; 3: R=Me). Further, with group 15 nucleophiles, the first structural characterized monosubstituted complexes with phosphanides could be obtained as P5 ligands containing exocyclic {PR2 } units (4: R=Cy, H; 5: R=Ph). These monoanionic complexes 2-5 were isolated and subsequent electrophilic quenching revealed novel types of neutral functionalized polyphosphorus complexes. These complexes bear formal chains of P5 R'R'' (6: R'=tBu, R'=Me) in a 1,3-disubstitution pattern or P6 R'R''R''' units (7: R'=Cy, R''=H, R'''=Me; 8: R'=Me, R''=Ph, R'''=Me) in a 1,1,3-substitution as middle-decks stabilized by one {Cp'''Co} and one {Cp*Fe} fragment. One-electron oxidation of 2, 3 or 5 by AgBF4 gave access to paramagnetic triple-decker complexes bearing P5 R middle-decks in various coordination fashions (R=tBu (10), R=PPh2 (12)). Interestingly, for R=Me (11), a dimerization is observed revealing a diamagnetic tetranuclear cluster containing a unique dihydrofulvalene-type P10 R2 ligand. All complexes were characterized by crystallographic and spectroscopic methods (EPR, multinuclear NMR and mass spectrometry) and their electronic structures were elucidated by DFT calculations.

Synthesis and Reactivity of a Cyclooctatetraene-Like Polyphosphorus Ligand Complex [Cyclo-P8 ].

The thermolysis of Cp'''Ta(CO)4 with white phosphorus (P4 ) gives access to [{Cp'''Ta}2 (µ,η2 : 2 : 2 : 2 : 1 : 1 -P8 )] (A), representing the first complex containing a cyclooctatetraene-like (COT) cyclo-P8 ligand. While ring sizes of n >6 have remained elusive for cyclo-Pn 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. Oxidation leads to dimerization to afford [{Cp'''Ta}4 (µ4 ,η2 : 2 : 2 : 2 : 2 : 2 : 2 : 2 : 1 : 1 : 1 : 1 -P16 )][TEF]2 (4, TEF=[Al(OC{CF3 }3 )4 ]- ). Reduction, however, leads to the fission of one P-P bond in A followed by rapid dimerization to form [K@[2.2.2]cryptand]2 [{Cp'''Ta}4 (µ4 ,η2 : 2 : 2 : 2 : 2 : 2 : 2 : 2 : 1 : 1 : 1 : 1 -P16 )] (5), which features an unprecedented chain-type P16 ligand. Lastly, A serves as a P2 synthon, via ring contraction to the triple-decker complex [{Cp'''Ta}2 (µ,η6 : 6 -P6 )] (B).

Reactivity of E4 (E4 =P4 , As4 , AsP3 ) towards Low-Valent Al(I) and Ga(I) Compounds.

The reactivity of yellow arsenic and the interpnictogen compound AsP3 towards low-valent group 13 compounds was investigated. The reactions of [LAl] (1, L=[{N(C6 H3 i Pr2 -2,6)C(Me)}2 CH]- ) with As4 and AsP3 lead to [(LAl)2 (µ,η1:1:1:1 -E4 )] (E4 =As4 (3 b), AsP3 (3 c)) by insertion of two fragments [LAl] into two of the six E-E edges of the E4 tetrahedra. Furthermore, the reaction of [LGa] (2) with E4 afforded [LGa(η1:1 -E4 )] (E4 =As4 (4 b), AsP3 (4 c)). In these compounds, only one E-E bond of the E4 tetrahedra was cleaved. These compounds represent the first examples of the conversion of yellow arsenic and AsP3 , respectively, with group 13 compounds. Furthermore, the reactivity of the gallium complexes towards unsaturated transition metal units or polypnictogen (En ) ligand complexes was investigated. This leads to the heterobimetallic compounds [(LGa)(µ,η2:1:1 -P4 )(LNi)] (5 a), [(Cp'''Co)(µ,η4:1:1 -E4 )(LGa)] (E=P (6 a), As (6 b), Cp'''=η5 -C5 H2 t Bu3 ) and [(Cp'''Ni)(η3:1:1 -E3 )(LGa)] (E=P (7 a), As (7 b)), which combine two different ligand systems in one complex (nacnac and Cp) as well as two different types of metals (main group and transition metals). The products were characterized by crystallographic and spectroscopic methods.

Actinide Pnictinidene Chemistry: A Terminal Thorium Parent-Arsinidene Complex Stabilised by a Super-Bulky Triamidoamine Ligand.

We report the direct synthesis of the terminal pnictidenes [An(TrenTCHS )(PnH)][M(2,2,2-cryptand)] (TrenTCHS ={N(CH2 CH2 NSiCy3 )3 }3- ; An/Pn/M=Th/P/Na 5, Th/As/K 6, U/P/Na 7, U/As/K 8) and their conversion to the pnictides [An(TrenTCHS )(PnH2 )] (An/Pn=Th/P 9, Th/As 10, U/P 11, U/As 12). Use of the super-bulky TrenTCHS ligand was essential to accessing complete families, and 6 is an unprecedented example of a terminal thorium-arsinidene complex and only the second structurally authenticated parent terminal arsinidene complex of any metal. Comparison of the terminal Th=AsH unit of 6 to the bridging ThAs(H)K linkage in structurally analogous [Th(TrenTIPS ){µ-As(H)K(15-crown-5)}] (TrenTIPS ={N(CH2 CH2 NSiPri 3 )3 }3- ) reveals a stronger Th-As bond in the former compared to the latter, and a large response overall to the nature of the Th=AsH bonding upon removal of the electrostatically-bound K-ion; the σ-bond changes little but the π-bond is significantly perturbed.

Halogenation and Nucleophilic Quenching: Two Routes to E-X Bond Formation in Cobalt Triple-Decker Complexes (E=As, P; X=F, Cl, Br, I).

The oxidation of [(Cp'''Co)2 (µ,η2 : η2 -E2 )2 ] (E=As (1), P (2); Cp'''=1,2,4-tri(tert-butyl)cyclopentadienyl) with halogens or halogen sources (I2 , PBr5 , PCl5 ) was investigated. For the arsenic derivative, the ionic compounds [(Cp'''Co)2 (µ,η4 : η4 -As4 X)][Y] (X=I, Y=[As6 I8 ]0.5 (3 a), Y=[Co2 Cl6-n In ]0.5 (n=0, 2, 4; 3 b); X=Br, Y=[Co2 Br6 ]0.5 (4); X=Cl, Y=[Co2 Cl6 ]0.5 (5)) were isolated. The oxidation of the phosphorus analogue 2 with bromine and chlorine sources yielded the ionic complexes [(Cp'''Co)2 (µ-PBr2 )2 (µ-Br)][Co2 Br6 ]0.5 (6 a), [(Cp'''Co)2 (µ-PCl2 )2 (µ-Cl)][Co2 Cl6 ]0.5 (6 b) and the neutral species [(Cp'''Co)2 (µ-PCl2 )(µ-PCl)(µ,η1 : η1 -P2 Cl3 ] (7), respectively. As an alternative approach, quenching of the dications [(Cp'''Co)2 (µ,η4 : η4 -E4 )][TEF]2 (TEF=[Al{OC(CF3 )3 }4 ]- , E=As (8), P (9)) with KI yielded [(Cp'''Co)2 (µ,η4 : η4 -As4 I)][I] (10), representing the homologue of 3, and the neutral complex [(Cp'''Co)(Cp'''CoI2 )(µ,η4 : η1 -P4 )] (11), respectively. The use of [(CH3 )4 N]F instead of KI leads to the formation of [(Cp'''Co)2 (µ-PF2 )(µ,η2 : η1 : η1 -P3 F2 )] (12) and 2, thereby revealing synthetic access to polyphosphorus compounds bearing P-F groups and avoiding the use of very strong fluorinating reagents, such as XeF2 , that are difficult to control.

Triple-decker complexes incorporating three distinct deck architectures.

The reactivity of the dilithioplumbole ([Li2(thf)2(µ,η5-LPb)], LPb = 1,4-bis-tert-butyl-dimethylsilyl-2,3-bis-phenyl-plumbolyl) towards the reactive pnictogen precursors P4, pentaphosphaferrocene, and pentaarsaferrocene ([Cp*Fe(η5-E5)] (Cp* = η5-C5Me5, E = P, As)) is reported. The reaction with P4 afforded a phospholyl lithium complex, via lead-phosphorus exchange, while the reactions with [Cp*Fe(η5-E5)] yielded the first examples of Pb-Fe-Li heterotrimetallic triple-decker polypnictogenides with three different deck motifs.

Structural diversity of mixed polypnictogen complexes: dicationic E2E'2 (E ≠ E' = P, As, Sb, Bi) chains, cycles and cages stabilized by transition metals.

The reactivity of the tetrahedral dipnictogen complexes [{CpMo(CO)2}2(µ,η2:η2-EE')] (E, E' = P, As, Sb, Bi; "Mo2EE'") towards different one-electron oxidation agents is reported. Oxidation with [Thia][TEF] (Thia+ = C12H8S2 +; TEF- = Al{OC(CF3)3}4 -) leads to the selective formation of the radical monocations [Mo2EE']˙+, which immediately dimerize to the unprecedented dicationic E2E'2 ligand complexes [{CpMo(CO)2}4(µ4,η2:η2:η2:η2-E'EEE')]2+ via E-E bond formation. Single crystal X-ray diffraction revealed that, in the case of Mo2PAs and Mo2PSb, P-P bond formation occurs yielding zigzag E2P2 (E = As (1), Sb (2)) chains, whereas Mo2SbBi forms a Sb2Bi2 (5) cage, Mo2AsSb an unprecedented As2Sb2 unit representing an intermediate stage between a chain- and a cage-type structure, and Mo2AsBi a novel planar As2Bi2 (4a) cycle. Therefore, 1-5 bear the first substituent-free, dicationic hetero-E4 ligands, stabilized by transition metal fragments. Furthermore, in the case of Mo2AsSb, the exchange of the counterion causes changes in the molecular structure yielding an unusual, cyclic As2Sb2 ligand. The experimental results are corroborated by DFT calculations.

A Structural Diversity of Molecular Alkaline-Earth-Metal Polyphosphides: From Supramolecular Wheel to Zintl Ion.

A series of molecular group 2 polyphosphides has been synthesized by using air-stable [Cp*Fe(η5 -P5 )] (Cp*=C5 Me5 ) or white phosphorus as polyphosphorus precursors. Different types of group 2 reagents such as organo-magnesium, mono-valent magnesium, and molecular calcium hydride complexes have been investigated to activate these polyphosphorus sources. The organo-magnesium complex [(Dipp BDI-Mg(CH3 ))2 ] (Dipp BDI={[2,6-i Pr2 C6 H3 NCMe]2 CH}- ) reacts with [Cp*Fe(η5 -P5 )] to give an unprecedented Mg/Fe-supramolecular wheel. Kinetically controlled activation of [Cp*Fe(η5 -P5 )] by different mono-valent magnesium complexes allowed the isolation of Mg-coordinated formally mono- and di-reduced products of [Cp*Fe(η5 -P5 )]. To obtain the first examples of molecular calcium-polyphosphides, a molecular calcium hydride complex was used to reduce the aromatic cyclo-P5 ring of [Cp*Fe(η5 -P5 )]. The Ca-Fe-polyphosphide is also characterized by quantum chemical calculations and compared with the corresponding Mg complex. Moreover, a calcium coordinated Zintl ion (P7 )3- was obtained by molecular calcium hydride mediated P4 reduction.

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

By reacting [{Cp‴Fe(CO)2}2(µ,η1:1-P4)] (1) with in situ generated phosphenium ions [Ph2P][A] ([A]- = [OTf]- = [O3SCF3]-, [PF6]-), a mixture of two main products of the composition [{Cp‴Fe(CO)2}2(µ,η1:1-P5(C6H5)2)][PF6] (2a and 3a) could be identified by extensive 31P NMR spectroscopic studies at 193 K. Compound 3a was also characterized by X-ray diffraction analysis, showing the rarely observed bicyclo[2.1.0]pentaphosphapentane unit. At room temperature, the novel compound [{Cp‴Fe}(µ,η4:1-P5Ph2){Cp‴(CO)2Fe}][PF6] (4) is formed by decarbonylation. Reacting 1 with in situ generated diphenyl arsenium ions gives short-lived intermediates at 193 K which disproportionate at room temperature into tetraphenyldiarsine and [{Cp‴Fe(CO)2}4(µ4,η1:1:1:1-P8)][OTf]2 (5) containing a tetracyclo[3.3.0.02,7.03,6]octaphosphaoctane ligand.

E4 Transfer (E=P, As) to Ni Complexes.

The use of [Cp''2 Zr(η1:1 -E4 )] (E=P (1 a), As (1 b), Cp''=1,3-di-tert-butyl-cyclopentadienyl) as phosphorus or arsenic source, respectively, gives access to novel stable polypnictogen transition metal complexes at ambient temperatures. The reaction of 1 a/1 b with [CpR NiBr]2 (CpR =CpBn (1,2,3,4,5-pentabenzyl-cyclopentadienyl), Cp''' (1,2,4-tri-tert-butyl-cyclopentadienyl)) was studied, to yield novel complexes depending on steric effects and stoichiometric ratios. Besides the transfer of the complete En unit, a degradation as well as aggregation can be observed. Thus, the prismane derivatives [(Cp'''Ni)2 (µ,η3:3 -E4 )] (2 a (E=P); 2 b (E=As)) or the arsenic containing cubane [(Cp'''Ni)3 (µ3 -As)(As4 )] (5) are formed. Furthermore, the bromine bridged cubanes of the type [(CpR Ni)3 {Ni(µ-Br)}(µ3 -E)4 ]2 (CpR =Cp''': 6 a (E=P), 6 b (E=As), CpR =CpBn : 8 a (E=P), 8 b (E=As)) can be isolated. Here, a stepwise transfer of En units is possible, with a cyclo-E4 2- ligand being introduced and unprecedented triple-decker compounds of the type [{(CpR Ni)3 Ni(µ3 -E)4 }2 (µ,η4:4 -E'4 )] (CpR =CpBn , Cp'''; E/E'=P, As) are obtained.

Synthesis and Multiple Subsequent Reactivity of Anionic cyclo-E3 Ligand Complexes (E=P, As).

A synthetic pathway for the synthesis of novel anionic sandwich complexes with a cyclo-E3 (E=P, As) ligand as an end deck was developed giving [Cp'''Co(η3 -E3 )]- (Cp'''=1,2,4-tri-tert-butylcyclopentadienyl, E=P ([5]), As ([6])) in good yields suitable for further reactivity studies. In the reaction with the chlorophosphanes R2 PCl (R=Ph, Cy, t Bu), neutral complexes with a disubstituted cyclo-E3 P (E=P, As) ligand in [Cp'''Co(η3 -E3 PR2 )] (E=P (7 a-c), As (9 a-c)) were obtained. These compounds can be partially or completely converted into complexes with a cyclo-E3 (E=P, As) ligand with an exocyclic {PR2 } unit in [Cp'''Co(η2 :η1 -E3 PR2 )] (E=P (8 a-c), As (10 a-c)). Additionally, the insertion of the chlorosilylene [LSiCl] (L=(t BuN)2 CPh) into the cyclo-E3 ligand of [5] and [6] was achieved and the novel heteroatomic complexes [Cp'''Co(η3 -E3 SiL)] (E=P (11), As (12)) could be isolated. The reaction pathway was elucidated by DFT calculations.

Redox Chemistry of Heterobimetallic Polypnictogen Triple-Decker Complexes - Rearrangement, Fragmentation and Transfer.

The redox chemistry of the heterobimetallic triple-decker complexes [(Cp*Fe)(Cp'''Co)(µ,η5 :η4 -E5 )] (E=P (1), As (2), Cp*=1,2,3,4,5-pentamethyl-cyclopentadienyl, Cp'''=1,2,4-tri-tertbutyl-cyclopentadienyl) and [(Cp'''Co)(Cp'''Ni)(µ,η3 :η3 -E3 )] (E=P (10), As (11)) was investigated. Compound 1 and 2 could be oxidized to the monocations 3 and 4 and further to the dications 5 and 6, while the initially folded cyclo-E5 ligand planarizes upon oxidation. The reduction leads to an opposite change in the geometry of the middle deck, which is now folded stronger into the direction of the other metal fragment (formation of monoanions 7 and 8). For the arsenic compound 8, a different behavior is found since a fragmentation into an As6 (9) and As3 ligand complex occurs. The Co and Ni triple-decker complexes 10 and 11 can be oxidized initially to the heterometallic monocations 12 and 13, which are not stable in solution and convert selectively into the homometallic nickel complexes 14 and 15 and the cobalt complexes 16 and 17. This behavior was further proven by the oxidation of [(Cp'''Co)(Cp''Ni)(µ,η3 :η2 -P3 )] (19, Cp''=1,3-di-tertbutyl-cyclopentadienyl) comprising two different Cp ligands. The transfer of {CpR M} fragments can be suppressed when a {W(CO)5 } unit is coordinated to the P3 ligand (20) prior to the oxidation and the mixed cobalt and nickel cation 21 can be isolated. The reduction of 10 and 11 yields the heterometallic monoanions 22 and 23, where no transfer of the {CpR M} fragments is observed.

Au-Containing Coordination Polymers Based on Polyphosphorus Ligand Complexes.

Whereas the self-assembly of pentaphosphaferrocenes [CpRFe(η5-P5)] (CpR = Cp*, Cp×, and CpBn) 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 [CpRFe(η5-P5)] with Au salts of different anions (GaCl4-, SbF6-, and Al(OC(CF3)3)4 (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. Thereby, a 2D coordination polymer comprising metal vacancies is isolated. In all products, the Au centers are coordinated in a linear or a trigonal planar environment. In solution, highly dynamic processes are observed. Variable-temperature NMR spectroscopy, solid-state NMR spectroscopy, and X-ray powder diffraction were applied to gain further insight into selected coordination compounds.