Studies of N-heterocyclic compounds with triosmium clusters: Formation of the heterocyclic-linked dicluster compound [Os 6(μ-H)2(μ3-C6H4N3)2(CO)18]

The cluster [Os₃(CO)₁₀(MeCN)₂] reacts with indazole (C₇H₆N₂) to give two isomeric products [0s₃(μ-H)(μ-C₇H₅N₂)(CO)₁₀] in which the five-membered ring has been metallated with N-H cleavage to give an N,N-bonded isomer or with C-H cleavage to give a C,N-bonded isomer. These two isomers have very similar X-ray structures but can be clearly distinguished by ¹H NMR methods. They are shown to correspond to related clusters derived from pyrazole. Benzotriazole (C₆H₅N₃) also reacts (as shown earlier by others) to give two isomers: an N,N-bonded species [Os₃(μ-H)(μ-C₆H₄N₃)(CO)₁₀] coordinated only through the five-membered ring and a minor C,N-bonded isomer [Os₃(μ-H)(μ-C₆H₄N₃)(CO)₁₀], metallated at the C₆ ring and coordinated through both rings. The former isomer reacts with Me₃NO in acetonitrile to give [Os₃(μ-H)(μ-C₆H₄N₃)(CO)₉(MeCN)] which thermally looses MeCN to produce the coupled product [Os₆(μ-H)₂(μ₃-C₆H₄N₃)₂(CO)₁₈] which was shown by X-ray structure determination to have all six nitrogen atoms coordinated to osmium, a novel situation for coordinated benzotriazole. The two Os₃ units are linked together by an OsNNOsNN ring in a boat conformation with the whole cluster adopting C₂ symmetry.     

Synthesis and crystal structures of (C8h8)Nd(C5H9C5H4) (THF)2 and [(C8H8)Gd(C5H9C4H4(THF)][(C8H8)GD(C5H9C5H4(THF)2]

LnCl₃ (Ln=Nd, Gd) reacts with C₅H₉C₅H₄Na (or K₂C₈H₈) in THF (C₅H₉C₅H₄ = cyclopentylcyclopentadienyl) in the ratio of 1 : to give (C₅H₉C₅H₄)LnCl₂(THF)_n (orC₈H₈)LnCl₂(THF)_n], which further reacts with K₂C₈H₈ (or C₅H₉C₅H₄Na) in THF to form the litle complexes. If Ln=Nd the complex (C₈H₈)Nd(C₅H₉C₅H₄)(THF)₂ (a) was obtained: when Ln=Gd the 1 : 1 complex [(C₈H₈)Gd(C_%H₉)(THF)][(C₈H₈)Gd(C₅H₉H₄)(THF)₂] (b) was obtained in crystalline form.

The crystal structure analysis shows that in (C₈H₈)Ln(C₅H₉C₅H₄)(THF)₂ (Ln=Nd or Gd), the Cyclopentylcyclopentadieny (η⁵), cyclooctatetraenyl (η⁸) and two oxygen atoms from THF are coordinated to Nd³⁺ (or Gd³⁺) with coordination number 10.

The centroid of the cyclopentadienyl ring (Cp′) in C₅H₉C₅H₄ group, cyclooctatetraenyl centroid (COTL) and two oxygens (THF) form a twisted tetrahedron around Nd³⁺ (or Gd³⁺). In (C₈H₈)Gd(C₅H₉C₅H₄)(THF), the cyclopentyl-cyclopentadienyl (η⁵), cyclooctatetraenyl (η⁸) and one oxygen atom are coordinated to Gd³⁺ with the coordination number of 9 and Cp′, COT and oxygen atom form a triangular plane around Gd³⁺, which is almost in the plane (dev. -0.0144 Å).     

Stability of the silicon-ruthenium bond in the presence of a strong nucleophile. Phase sensitive H NMR COSY and crystal structure of Ru(CO)2(NH2CH2C6H5)2(Si(C6H5)(CH3)2)I

The ruthenium(II) complex Ru(CO)₂(NH₂(NH₂CH₂C₆H₅)₂(Si(C₆H₅)(CH₃)₂)I has been prepared by the reaction of Ru(CO)₄(Si(C₆H₅)(CH₃)₂)I with benzylamine. Two-dimensional homonuclear ¹H NMR experiments examine the scalar coupling of the enantiotopic amino and methylene protons of the benzylamine ligand. X-ray analysis of Ru(CO)₂(NH₂CH₂C₆H₅)₂(Si(C₆H₅)(CH₃)₂)I·1/3C₅H₁₂ (triclinic; P ; a = 14.266(4), b = 15.748(5), c = 20.082(6) Å; = 94.38(3), β = 96.30(2), γ = 101.52(2)°) indicates three crystallographically unique complexes form a clathrate with a pentane guest.     

Thermal decomposition study on mixed ligand thymine complexes of divalent nickel(II) with dianions of some dicarboxylic acids

Thermal decomposition of mixed ligand thymine (2,4-dihydroxy-5-methylpyrimidine) complexes of divalent Ni(II) with aspartate, glutamate and ADA (N-2-acetamido)iminodiacetate dianions was monitored by TG, DTG and DTA analysis in static atmosphere of air. The decomposition course and steps of complexes [Ni(C₅H₆N₂O₂)(C₄H₅NO₄)²⁻(H₂O)₂]·H₂O, [Ni(C₅H₆N₂O₂)(C₅H₇NO₄)²⁻(H₂O)₂]·H₂O and [Ni(C₅H₆N₂O₂)(C₆H₈N₂O₅)²⁻(H₂O)₂]·1.5H₂O were analyzed. The final decomposition products are found to be the corresponding metal oxides. The kinetic parameters namely, activation energy (E*), enthalpy (ΔH*), entropy (ΔS*) and free energy change of decomposition (ΔG*) are calculated from the TG curves using Coats–Redfern and Horowitz–Metzger equations. The stability order found for these complexes follows the trend aspartate > ADA > glutamate.     

The tungsten-tungsten triple bond---18. Bridging and terminal allyl ligands in complexes of the formula W2(R)2(NMe2)4, where R = C3H5 and C4H7

The reaction between RMgCl (two equivalents) and 1,2-W₂Cl₂(NMe₂)₄ in hydrocarbon solvents affords the compounds W₂R₂(NMe₂)₄, where R = allyl and 1− and 2-methyl-allyl. In the solid state the molecular structure of W₂(C₃H₅)₂(NMe₂)₄ has C₂ symmetry with bridging allyl ligands and terminal W---NMe₂ ligands. The W---W distance 2.480(1) Å and the C---C distances, 1.47(1) Å, imply an extensive mixing of the allyl π-MOs with the WW π-MOs, and this is supported by an MO calculation on the molecule W₂(C₃H₅)₂(NH₂)₄ employing the method of Fenske and Hall. The most notable interaction is the ability of the (WW)⁶⁺ centre to donate to the allyl π^*-MO (π₃). This interaction is largely responsible for the long W---W distance, as well as the long C---C distances, in the allyl ligand. The structure of the 2-methyl-allyl derivative W₂(C₄H₇)₂(NMe₂)₄ in the solid state reveals a gauche-W₂C₂N₄ core with W---W = 2.286(1) Å and W---C = 2.18(1) Å, typical of WW and W---C triple and single bonds, respectively. In solution (toluene-d₈) ¹H and ¹³C NMR spectra over a temperature range −80°C to +60°C indicate that both anti- and gauche- W₂C₂N₄ rotamers are present for the 2-methyl-allyl derivative. In addition, there is a facile fluxional process that equilibrates both ends of the 2-methyl-allyl ligand on the NMR time-scale. This process leads to a coalescence at 100°C and is believed to take place via an η³-bound intermediate. The 1-methyl-allyl derivative also binds in an η¹ fashion in solution and temperature-dependent rotations about the W---N, W---C and C=C bonds are frozen out at low temperatures. The spectra of the allyl compound W₂(C₃H₅)₂(NMe₂)₄ revealed the presence of two isomers in solution—one of which can be readily reconciled with the presence of the bridging isomer found in the solid state while the other is proposed to be W₂(η³-C₃H₅)₂(NMe₂)₄. The compound W₂R₂(NMe₂)₄ where R = 2,4-dimethyl- pentadiene was similarly prepared and displayed dynamic NMR behaviour explainable in terms of facile η¹ = η³ interconversions.     

The reaction of cis dioxobis(2,4 pentanedionato)molybdenum (VI) and 2,2′ pyridylbenzoxazole (L), a novel route to β[Mo8O26]

MoO₂(C₅H₇O₂)₂, where C₅H₇O₂ is 2,4-pentanedione (acac), reacts with 2-2′ pyridylbenzoxazole in acetone to give a product with stoichiometry, Mo₃C₂₄H₁₆N₆O₁₂. This product dissolves readily in dimethylformamide to give a brown solution which on standing for several weeks yielded crystals. An X-ray structure determination showed these crystals to contain uncoordinated 2-2′pyridylbenzoxazole and [(CH₃)₂NH₂]₄⁺[Mo₈O₂₆]⁴⁻.     

Novel supramolecular compounds with three-dimensional hydrogen-bonded network [M(H2O)6][H2L] (H4L=1,2,4,5-benzenetetracarboxylic acid, M=Mn and Co): syntheses, characterization and crystal structures

Two hydrogen-bonded supramolecular compounds having the general formula [M(H₂O)₆][H₂L] (M=Mn^II or Co^II and H₄L=1,2,4,5-benzenetetracarboxylic acid), have been newly prepared by the reaction of [M(H₂O)₆](ClO₄)₂ and [C₆H₂(COOH)₄] (H₄L), and structurally characterized by X-ray diffraction. The metal center in each compound is six-coordinated, forming an ideal octahedral geometry. Both neutral formula units make unique three-dimensional supramolecular architectures through hydrogen bonds and stabilized by electrostatic force.     

Crystallization of Ammonium Nitrate Under Organised Monolayers at Air-Aqueous Interface

The crystallization of NH₄NO₃ under compressed Langmuir monolayers of carboxybe-taine(C₂₂N₃COO^-),C₂₂H₁₅N(CH₂)₃(CH₂)₃COO^--[C₂₂N₃COO^-] and dioleoyl-L-a-lecithin(DOPC) was studied by means of π-A. ΔV-A and fluorescence microscopy (FM). The surface pressure, surface potential and molecular area of C₂₂N₃COO^- were decreased on the NH₄NO₃ solution subphase. The surface pressure and molecular area of DOPC was increased. The surface potential of DOPC was decreased. We can directly observe the surface crystallization of NH₄NO₃ by FM. The results revaled that C₂₂N₃COO^- monolayer was the promoter of NH₄NO₃ surface crystallization. In contrast,DOPC monolayer was the inhibitor of the surface crystallization of NH₄NO₃.     

Novel iodoammonium cations: Synthesis and characterization of o-C6H4(NH2)2IX (X = I, AsF6, AlI4)

The new iodoammonium salts o-C₆H₄(NH₂)₂I⁺I⁻ (1) and o-C₆H₄(NH₂)₂I⁺ AsF₆⁻ (2) were prepared by reaction of o-phenylene diamine with I₂ or I₃⁺AsF₆⁻, respectively. Compound 1 reacts with AlI₃ yielding quantitatively the corresponding tetraiodoaluminate o-C₆H₄(NH₂)₂I⁺AlI₄⁻ (3). The species were characterized by chemical analysis, vibrational (IR and Raman) and temperature-dependent ¹H NMR spectropscopy. Direct evidence for a N---I bond was found in the Raman spectra of 1, 2 and 3 (ν(NI) = 599–600 cm⁻¹).     

Homo- and hetero-bridged mixed-valence dinuclear complexes which contain the fragment ‘Rh(C6F5)3’

The reaction of the anionic mononuclear rhodium complex [Rh(C₆F₅)₃Cl(Hpz)]^t- (Hpz = pyrazole, C₃H₄N₂) with methoxo or acetylacetonate complexes of Rh or Ir led to the heterodinuclear anionic compounds [(C₆F₅)₃Rh(μ-Cl)(μ-pz)M(L₂)] [M = Rh, L₂ = cyclo-octa-1,5-diene, COD (1), tetrafluorobenzobarrelene, TFB (2) or (CO)₂ (4); M = Ir, L₂ = COD (3)]. The complex [Rh(C₆F₅)₃(Hbim)]⁻ (5) has been prepared by treating [Rh(C₆F₅)₃(acac)]⁻ with H₂bim (acac = acetylacetonate; H₂bim = 2,2′-biimidazole). Complex 5 also reacts with Rh or Ir methoxo, or with Pd acetylacetonate, complexes affording the heterodinuclear complexes [(C₆F₅)₃Rh(μ-bim)M(L₂)]⁻ [M = Rh, L₂ = COD (6) or TFB (7); M = Ir, L₂ = COD (8); M = Pd, L₂ = η³-C₃H₅ (9)]. With [Rh(acac)(CO)₂], complex 5 yields the tetranuclear complex [{(C₆F₅)₃Rh(μ-bim)Rh(CO)₂}₂]₂₋. Homodinuclear Rh^III derivatives [{Rh(C₆F₅)₃}₂(μ-L)₂]^·- [L₂ = OH, pz (11); OH, S^tBu (12); OH, SPh (13); bim (14)] have been obtained by substitution of one or both hydroxo groups of the dianion [{Rh(C₆F₅)₃(μ-OH)}₂]²⁻ by the corresponding ligands. The reaction of [Rh(C₆F₅)₃(Et₂O)_x] with [PdX₂(COD)] produces neutral heterodinuclear compounds [(C₆F₅)₃Rh(μ-X)₂Pd(COD)] [X = Cl (15); Br (16)]. The anionic complexes 1–14 have been isolated as the benzyltriphenylphosphonium (PBzPh₃⁺) salts.     

Hydrothermal syntheses and crystal structures of bimetallic cluster complexes [{Cd(phen)2}2V4O12]·5H2O and [Ni(phen)3]2[V4O12]·17.5H2O

The hydrothermal reactions of vanadium oxide starting materials with divalent transition metal cations in the presence of nitrogen donor chelating ligands yield the bimetallic cluster complexes with the formulae [{Cd(phen₂)₂V₄O₁₂]·5H₂O (1) and [Ni(phen)₃]₂[V₄O₁₂]·17.5H₂O (2). Crystal data: C₄₈H₅₂Cd₂N₈O₂₂V₄ (1), triclinic. a=10.3366(10), b=11.320(3), c=13.268(3) Å, =103.888(17)°, β=92.256(15)°, γ=107.444(14)°, Z=1; C₇₂H₁₃₁N₁₂Ni₂O_29.5V₄ (2), triclinic. a=12.305(3), b=13.172(6), c=15.133(4), =79.05(3)°, β=76.09(2)°, γ=74.66(3)°, Z=1. Data were collected on a Siemens P4 four-circle diffractometer at 293 K in the range 1.59° <θ<26.02° and 2.01°<θ<25.01° using the ω-scan technique, respectively. The structure of 1 consists of a [V₄O₁₂]⁴⁻ cluster covalently attached to two {Cd(phen)₂}²⁺ fragments, in which the [V₄O₁₂]⁴⁻ cluster adopts a chair-like configuration. In the structure of 2, the [V₄O₁₂]⁴⁻ cluster is isolated. And the complex formed a layer structure via hydrogen bonds between the [V₄O₁₂]⁴⁻ unit and crystallization water molecules.     

The decomposition of C4H8 complexes at controlled internal energies

A coincidence technique is used to study the influence of the internal energy of the reactant ion on the cross section of the ion-molecule reactions in the C₂H₄⁺ + C₂H₄ system. The experiment is performed at thermal collision energies. In the ion-molecule reactions of C₂H₄⁺ + C₂H₄ our measurements indicate a barrier between the initially formed collision complex (C₂H₄)₂⁺* and a tight complex (C₄H₈⁺)*. Using an extension of our earlier developed statistical model, now including a potential barrier between the initially formed loose complex (C₂H₄)₂⁺* and the tight complex (C₄H₈⁺)*, our experimental data can be reproduced. For comparison also the internal energy dependence of the unimolecular decomposition of photoionised 1-C₄H₈⁺ is measured. Assuming that the photoionised 1-C₄H₈⁺ is identical with the tight (C₄H₈⁺)* complex, the model applied to the ion-molecule reactions describes also the unimolecular decay of 1-C₄H₈⁺ correctly, using the same set of parameters.     

Dimethylchalkogenide als liganden in kationischen cyclopentadienyleisen-bis(phosphin)-komplexen: synthese, reaktivität und kristallstruktur von [C5H5Fe(P(OCH3)3)2(S(CH3)2)]PF6

Thermal displacement of coordinated nitriles RCN (R = CH₃, C₂H₅ or n-C₃H₇) in [C₅H₅Fe(L₂)(NCR)]X complexes (L₂ = P(OCH₃)₃)₂, (P(OC₆H₅)₃)₂ or (C₆H₅)₂PC₂H₄P(C₆H₅)₂ (DPPE)) by E(CH₃)₂ affords high yields of [C₅H₅Fe(L₂)(E(CH₃)₂)]X compounds (E = S, Se and Te; X = BF₄ or PF₆). Spectroscopic data and ligand displacement reactions are presented and discussed together with related observations on [C₅H₅Fe(CO)₂(E(CH₃)₂)]BF₄ compounds. The molecular structure of [C₅H₅Fe(P(OCH₃)₃)₂(S(CH₃)₂)]PF₆ was determined by a single-crystal X-ray diffraction study: monoclinic, space group P2₁/n-C⁵_2h (No. 14) with a = 8.4064(12), b = 11.183(2), c = 50.726(8) Å, β = 90.672(13)° and Z = 8 molecules per unit cell. The coordination sphere of the iron atom is pseudo-tetrahedral with an Fe---S bond distance of 2.238 Å.     

Synthesis,structural study,thermal, optical properties and characterization of the new compound [C_6H_7N_2O_2]_3TeCl_5·2Cl

The new organic-inorganic compound, [C_6H_7N_2O_2]_3TeCl_5·2Cl was synthesized and its structure was determined at room temperature in the triclinic system (P~-1) with the following parameters: a = 10.5330(11) ?, b = 10.6663(11) ?, c = 15.9751(16)?, α = 82.090(2)°, β = 71.193(2)°, γ = 68.284(2)°and Z = 2. The final cycle of refinement led to R = 0.057 and Rw = 0.149. The crystal structure was stabilized by an extensive network of N--H···Cl and non-classical C--H···Cl hydrogen bonds between the cation and the anionic group. Several thermal analysis techniques such as thermogravimetric analysis, differential scanning calorimetric analysis and evolved gas analysis were used. We used isoconversional kinetics methods to determine the kinetics parameters. We observe that the decomposition of [C_6H_7N_2O_2]_3TeCl_5·2Cl entails the formation hydrochloric acid of nitroaniline as volatiles. The infrared spectra were recorded in the4000–400 cm~(-1)frequency region. The Raman spectra were recorded in the external region of the anionic sublattice vibration 50–1500 cm~(-1). The optical band gap was calculated from the UV-Vis absorbance spectra using classical Tauc relation which was found to be 3.12 and 3.67 eV.     

Thermal studies on the electrical conductivity of some (CnH2n+1NH3)2CuCl4 (n = 1,2) and (CH2)(CH3)2CuCl4 complexes

The electrical conductivities of the compounds (CH₃NH₃)₂CuCl₄, (C₂H₅NH₃)₂CuCl₄ and (CH₂)₂(NH₃)₂CuCl₄ were measured in the temperature range which includes their structural phase transition. The values of the activation energies as calculated from the Arrhenius equation are reported. Confirmation of the phase transition temperatures is carried out using differential thermal analysis in the same temperature range as the conductivity measurements.     

Synthesis and X-ray structure of the Mo(VI) species Mo4O12(C12H30N4S2)2(C3H7ON)n (n ≈ 2)

Dissolution of Mo₂O₅((CH₃)₂NCH₂CH₂NHCH₂CH₂S)₂ in dimethylformamide results in the formation of a species without coordinated sulphur, as indicated by ⁹⁵Mo NMR spectroscopy. Subsequent crystallization of this solution yielded the compound Mo₄O₁₂(C₁₂H₃₀N₄S₂)₂(C₃H₇ON)₂ which X-ray crystallography shows to consist of a novel Mo₄O₁₂ core, containing an eight-membered Mo₄O₄ ring with the two pairs of diagonal molybdenum atoms linked by disulphido-containing groups.     

Crystal structure, phase transition and thermal behaviour of dabcodiium hexaaquacopper(II) bis(sulfate), (C6H14N2)[Cu(H2O)6](SO4)2

A new organically templated metal sulfate has been synthesized and characterized. At room temperature, dabcodiium hexaaquacopper(II) bis(sulfate), (C₆H₁₄N₂)[Cu(H₂O)₆](SO₄)₂ crystallizes in the monoclinic symmetry (space group P2₁/n) with the following unit cell parameters: a = 6.9533(2), b = 12.5568(2), c = 9.9434(2) Å; β = 90.526(1)° and Z = 2. Its crystal structure is built from isolated [Cu(H₂O)₆]²⁺, and disordered ions linked together by a hydrogen-bonding network. The title compound undergoes a reversible phase transition of the first-order type at 265.7/281.8 K on heating–cooling runs. Below the phase transition temperature, the structure is fully ordered.     

A localized molecular orbital study on the bonding of> Mo3S4]2Mo> and> Mo3S4]CuI> versus (C6H6)2Cr and C6H6Cr(CO)3

The energy-localized CNDO/2 molecular orbitais have been calculated for the clusters containing molybdenum, > {Mo₃S₄₂Mo}⁸⁺ and> Mo₃S₄]CuI> ⁴⁺, versus the prototype arene-metal sandwich (C₆H₆)₂Cr and half-sandwich complexes C₆H₆Cr(CO)₃. The bonding characteristics of these compounds are described from a localization bonding viewpoint. There are two typical M-arene and M-[Mo₃S₄] bondings. One is formed by electron donation from the three-center two-electron π-bonds in the arene or [Mo₃S₄]⁴⁺ ligands into the vacant hybrid orbitais of the “stranger” metal atom. In the other M-arene or M-[Mo₃S₄] bond there is very little donation by the lone electron pair occupying the d AOs of the “stranger” metal atom to the arene or [Mo₃S₄]⁴⁺ ligands. The analogy of the ligand [Mo₃S₄]⁴⁺ in the clusters studied with the ligand benzene is also briefly discussed.     

Synthesis, structure and properties of delocalized transition metal chelates: Diazoketiminato chelates of Co(III) and Pt(II)

The reactions of HL 1 [where HL is 1N-(2-pyridyl-2-methyl)-2-arylazoaniline and is formulated as ArN = NC₆H₄N(H)(CH₂C₅H₄N); Ar = C₆H₅ (for HL¹) or p-MeC₆H₄ (for HL²) or p-ClC₆H₄ (for HL³)] with K₂PtCl₄ and Co(ClO₄)₃ · 6H₂O afforded the (L)PtCl and [(L)₂Co]ClO₄ complexes, respectively. The HL ligands bind the platinum(II) and cobalt(III) centres in a tridentate (N,N,N) fashion, forming new diazoketiminato chelates upon dissociating the amino proton. The X-ray structures of (L³)PtCl and [(L³)₂Co]ClO₄ were determined. Redox properties of the new complexes have been examined.     

Synthesis of metallocenes of zirconium, hafnium, manganese, iron, tin, lead and half-sandwich complexes of rhodium and iridium containing the ligands (η-C5R4CR′2PMe2), where R and R′ may be H or Me

The dimethylphosphino substituted cyclopentadienyl precursor compounds [M(C₅Me₄CH₂PMe₂)], where M=Li⁺ (1), Na⁺ (2), or K⁺ (3), and [Li(C₅H₄CR′₂PMe₂)], where R′₂=Me₂ (4), or (CH₂)₅ (5), [HC₅Me₄CH₂PMe₂H]X, where X⁻=Cl⁻ (6) or PF₆⁻ (7) and [HC₅Me₄CH₂PMe₂] (8), are described. They have been used to prepare new metallocene compounds, of which representative examples are [Fe(η-C₅R₄CR′₂PMe₂)₂], where R=Me, R′=H (9); R=H and R′₂=Me₂ (10), or (CH₂)₅ (11), [Fe(η-C₅H₄CMe₂PMe₃)₂]I₂ (12), [Fe{η-C₅Me₄CH₂P(O)Me₂}₂] (13), [Zr(η-C₅R₄CR′₂PMe₂)₂Cl₂], where R=H, R′=Me (14), or R=Me, R′=H (15), [Hf(η-C₅H₄CMe₂PMe₂)₂]Cl₂] (16), [Zr(η-C₅H₄CMe₂PMe₂)₂Me₂] (17), {[Zr(η-C₅Me₄CH₂PMe₂)₂]Cl}{(C₆F₅)₃BClB(C₆F₅)₃} (18), [Zr{(η-C₅Me₄CH₂PMe₂)₂Cl₂}PtI₂] (19), [Mn(η-C₅Me₄CH₂PMe₂)₂] (20), [Mn{(η-C₅Me₄CH₂PMe₂B(C₆F₅)₃}₂] (21), [Pb(η-C₅H₄CMe₂PMe₂)₂] (23), [Sn(η-C₅H₄CMe₂PMe₂)₂] (24), [Pb{η-C₅H₄CMe₂PMe₂B(C₆F₅)₃}₂] (25), [Pb(η-C₅H₄CMe₂PMe₂)₂PtI₂] (26), [Rh(η-C₅Me₄CH₂PMe₂)(C₂H₄)] 29, [M(η,κP-C₅Me₄CH₂PMe₂)I₂], where M=Rh (30), or Ir, (31).