Solvent and salt effects on the kinetics of the reaction between [Ru(NH3)5pz]2+ and [Fe(CN)5H2O]3–

The kinetics of replacement of H₂O by [Ru(NH₃)pz]²⁺ (pz = pyrazine) in [Fe(CN)₅H₂O]^3? have been studied in various concentrated electrolyte solutions and in various water–cosolvent mixtures, at 298 K. Salt and cosolvent effects can be rationalized taking into account specific medium effects on both the encounter complex formation process and the ligand‐substitution process, once the encounter complex is formed. These effects in water–cosolvent mixtures depend on the solvation of the reactants by the components of the mixture, as well as on the solvent–solvent interactions in these mixtures. Salt effects seem to be related to a primary salt effect as well as to the effect of the cations on the electronic density on the iron complex. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 367–373, 2003     

[NH3(CH2)6NH3][P2V5O17]·3.83H2O: A new 3D Organic‐templated Vanadophosphate with Extra‐large 16‐Membered Ring Constructed from Nanosized P–O–V Wheels

A new porous 3D vanadophosphate, [NH₃(CH₂)₆NH₃][P₂V₅O₁₇] · 3.83H₂O ( 1 ) is synthesized by using NH₂(CH₂)₆NH₂ as template, and characterized by single crystal structural analysis, X‐ray diffraction, IR spectroscopy, TG analysis, and powder XRD. Single crystal analysis shows that compound 1 crystallizes in cubic shape, space group Im m with cell dimensions: a = b = c = 26.5068(8) Å, V = 18624.0(10) Å³, Z = 24. Structural refinement indicates that the inorganic framework of 1 is constructed from nanosized P–O–V wheels.     

Co(NH3)2Cl2 and Co(ND3)2Cl2: Order‐Disorder Behaviour of N(H, D)3 and Antiferromagnetic Structure

Diammine cobalt(II) chloride, Co(N(H, D)₃)₂Cl₂ was prepared by decomposition of the corresponding hexaammines at 120 °C in dynamical vacuum. Crystal structures and magnetic properties of these materials were characterised by X‐ray and neutron powder diffraction, and heat capacity measurements. At ambient temperatures Co(N(H, D)₃)₂Cl₂ crystallises in the Cd(NH₃)₂Cl₂ type structure: space group Cmmm, Z = 2, a = 8.0512(2) Å, b = 8.0525(2) Å, c = 3.73318(9) Å (X‐ray data of the H compound). This structure consists of chains of edge‐sharing octahedra [CoCl_4/2(NH₃)₂] running along the c‐axis. Neutron diffraction confirms that that the ND₃ groups are rotationally disordered at ambient temperatures. At 1.5 K and 20 K neutron diffraction data reveal rotational ordering of the ND₃ groups leading to doubling of the c‐axis and to Ibmm symmetry: a = 7.9999(6) Å, b = 7.9911(5) Å, c = 7.4033(3) Å (Z = 4, values for T = 1.5 K). Furthermore, antiferromagnetic ordering is present at these temperatures. It is caused by a ferromagnetic coupling of the magnetic moments at Co²⁺ (3.60(5) μ_B at 1.5 K, 3.22(5) μ_B at 20 K) along the octahedra chains [CoCl_4/2(NH₃)₂] and antiferromagnetic coupling between neighbouring chains. According to heat capacity measurements the phase transition antiferromagnetic‐paramagnetic takes place at T_N = 26 K.     

Chloro‐N′,N′‐dimethylformamidinium‐(dimethylcyanamid)trichloroberyllat, [Me2NC(Cl)NH2]+[BeCl3(NCNMe2)]−

Chloro‐N′,N′‐dimethylformamidinium‐(dimethylcyanamide)trichloroberyllate, [Me₂NC(Cl)NH₂]⁺[BeCl₃(NCNMe₂)]^? Chloro‐N′,N′‐dimethylformamidinium‐(dimethylcyanamide)trichloroberyllate, [Me₂NC(Cl)NH₂]⁺[BeCl₃(NCNMe₂)]^? was prepared from BeCl₂ with two equivalents of dimethylcyanamide in CH₂Cl₂ suspension. The compound was characterized by X‐ray crystallography and by IR spectroscopy. Space group , Z = 2, lattice dimensions at 193 K: a = 620.7(1), b = 744.9(2), c = 1520.3(3) pm, α = 96.87(2)°, β = 100.41(2)°, γ = 100.17(2)°, R₁ = 0.0443. Cations and anions form N–H…Cl hydrogen bridges along [010].     

Synthesis and Structure of a One‐Dimensional Aluminum Phosphate, [NH3(CH2)2NH2(CH2)3NH3]3+ [Al(PO4)2]3—

A one‐dimensional aluminum phosphate, [NH₃(CH₂)₂NH₂(CH₂)₃NH₃]³⁺ [Al(PO₄)₂]^3—, has been synthesized hydrothermally in the presence of N‐(2‐Aminoethyl‐)1, 3‐diaminopropane (AEDAP) and its structure determined by single crystal X‐ray diffraction. Crystal data: space group = Pbca (no. 61), a = 16.850(2), b = 8.832(1), c = 17.688(4)Å, V = 2632.4(2)ų, Z = 8, R₁ = 0.0389 [5663 observed reflections with I > 2σ(I)]. The structure consists of anionic [Al(PO₄)₂]^3— chains built up from AlO₄ and PO₄ tetrahedra, in which all the AlO₄ vertices are shared and each PO₄ tetrahedron possesses two terminal P=O linkages. The cations, which balances the negative charge of the chains, are located in between the chains and interact with the oxygen atoms through strong N—H···O hydrogen bonds. Additional characterization of the compound by powder XRD and MAS‐NMR has also been performed and described.     

Metal‐Organic Niccolite: Synthesis,Structures, Phase Transition,and Magnetic Properties of [CH3NH2(CH2)2NH2CH3][M2(HCOO)6] (M=divalent Mn,Fe, Co,Ni, Cu and Zn)

We report the synthesis, crystal structures, thermal and magnetic characterizations of a family of metal‐organic frameworks adopting the niccolite (NiAs) structure, [dmenH₂²⁺][M₂(HCOO)₆²⁻] (dmen=N,N′‐dimethylethylenediamine; M=divalent Mn, 1Mn ; Fe, 2Fe ; Co, 3Co ; Ni, 4Ni ; Cu, 5Cu ; and Zn, 6Zn ). The compounds could be synthesized by either a diffusion method or directly mixing reactants in methanol or methanol–water mixed solvents. The five members, 1Mn , 2Fe , 3Co , 4Ni , and 6Zn are isostructural and crystallize in the trigonal space group P 1c, while 5Cu crystallizes in C2/c. In the structures, the octahedrally coordinated metal ions are connected by anti–anti formate bridges, thus forming the anionic NiAs‐type frameworks of [M₂(HCOO)₆²⁻], with dmenH₂²⁺ located in the cavities of the frameworks. Owing to the Jahn–Teller effect of the Cu²⁺ ion, the 3D framework of 5Cu consists of zigzag Cu‐formate chains with Cu OCHO Cu connections through short basal Cu O bonds, further linked by the long axial Cu O bonds. 6Zn exhibits a phase transition probably as a result of the order–disorder transition of the dmenH₂²⁺ cation around 300 K, confirmed by differential scanning calorimetry and single crystal X‐ray diffraction patterns under different temperatures. Magnetic investigation reveals that the four magnetic members, 1Mn , 2Fe , 3Co , and 4Ni , display spin‐canted antiferromagnetism, with a Néel temperature of 8.6 K, 19.8 K, 16.4 K, and 33.7 K, respectively. The Mn, Fe, and Ni members show spin‐flop transitions below 50 kOe. 2Fe possesses a large hysteresis loop with a large coercive field of 10.8 kOe. The Cu member, 5Cu , shows overall antiferromagnetism (both inter‐ and intra‐chains) with low‐dimensional characteristics.     

First Characterization of an Extended Ammonium‐Ammonia Complex [{NH4(NH3)4}+(μ‐NH3)2] in the Crystal Structure of [NH4(NH3)4][Co(C2B9H11)2] · 2 NH3

The compound [NH₄(NH₃)₄][Co(C₂B₉H₁₁)₂] · 2 NH₃ ( 1 ) was prepared by the reaction of Na[Co(C₂B₉H₁₁)₂] with a proton‐charged ion‐exchange resin in liquid ammonia. The ammoniate 1 was characterized by low temperature single‐crystal X‐ray structure analysis. The anionic part of the structure consists of [Co(C₂B₉H₁₁)₂]^‐ complexes, which are connected via C‐H···H‐B dihydrogen bonds. Furthermore, 1 contains an infinite equation/tex2gif-stack-2.gif[{NH₄(NH₃)₄}⁺(μ‐NH₃)₂] cationic chain, which is formed by [NH₄(NH₃)₄]⁺ ions linked by two ammonia molecules. The N‐H···N hydrogen bonds range from 1.92 to 2.71Å (DHA = Donor···Acceptor angles: 136‐176°). Additional N‐H···H‐B dihydrogen bonds are observed (H···H: 2.3‐2.4Å).     

Homoleptic Octahedral Methylamine Complexes of Manganese(II): Solvothermal Syntheses and Crystal Structures of [Mn(NH2CH3)6]Cl2 and the Pentaselenide [Mn(NH2CH3)6]Se5

[Mn(NH₂CH₃)₆]Cl₂ ( 1 ) and [Mn(NH₂CH₃)₆]Se₅ ( 2 ) were prepared by solvothermal reactions in liquid methylamine from MnCl₂ at 150 °C for 1 and from a mixture of MnCl₂, Rb₂Se and selenium at 120 °C for 2 . Both 1 and 2 were obtained in high yields as colorless and dark‐red crystals and represent the first homoleptic methylamine complexes with coordination number six. Compound 1 crystallizes rhombohedral (R$\bar{3}$ , Z = 3) and is built of only slightly distorted octahedral [Mn(NH₂CH₃)₆]²⁺ cations and Cl^– anions. Compound 2 crystallizes orthorhombic (Pnna, Z = 4) and is built of octahedral [Mn(NH₂CH₃)₆]²⁺ cations showing a strong angular distortion and of Se₅^2– anions in the form of chains in transoid conformation. DFT calculations reveal an almost undistorted ground state structure for [Mn(NH₂CH₃)₆]²⁺ with N–Mn–N angular distortions of 1° from orthogonality, close to the structure found for the complex in 1 . The calculated energy necessary for a distortion as found in the structure of 2 is rather low and amounts to 26 kJmol^–1 which is in the range typical for hydrogen bonds. The N–Mn–N angular distortions of the complex cation in 2 , observed in the range of 10°, is caused by cation‐anion interactions in the crystal structure by N–H ···· Se hydrogen bonds.     

A shock tube study of H + HNCO → NH2 + CO

The reaction of atomic hydrogen with isocyanic acid (HNCO) to produce the amidogen radical (NH₂) and carbon monoxide, has been studied in shock-heated mixtures of HNCO dilute in argon. Time-histories of the ground-state NH₂ radical were measured behind reflected shock waves using cw, narrowlinewidth laser absorption at 597 nm, and HNCO time-histories were measured using infrared emission from the fundamental v₂-band of HNCO near 5 μm. The second-order rate coefficient of reaction (2(a)) was determined to be: cm³ mol^?1 s^?1, where f and F define the lower and upper uncertainty limits, respectively. An upper limit on the rate coefficient of was determined to be:      

The Complex Amide K2[Zr(NH2)6]

We present the low‐temperature synthesis of potassium hexaamido zirconate(IV) from the transition metal tetrafluoride and thealkali metal dissolved in liquid ammonia at –40 °C. Potassium hexaamido zirconate(IV) K₂[Zr(NH₂)₆] is the first ternary amide reported for elements of group 4 of the periodic table It crystallizes with a novel structure type in the trigonal space group R$\bar{3}$ c with a = 6.5422(2) Å, c = 32.824(2) Å, V = 1216.66(9) Å³, Z = 6 and c/a = 5.017. The structure can be derived from the K₂PtCl₆ type. The compound contains discrete D₃‐symmetric [Zr(NH₂)₆]^2– anions which differ significantly from octahedral shape. Quantum chemical calculations show the distortion to arise from a splitting of degenerate d‐orbitals on the zirconium atom leading to a significant gain in energy.     

Lanthanide(III) Complexes of 2‐[4,7,10‐Tris(phosphonomethyl)‐1,4,7,10‐tetraazacyclododecan‐1‐yl]acetic Acid (H7DOA3P): Multinuclear‐NMR and Kinetic Studies

The protonation constants of 2‐[4,7,10‐tris(phosphonomethyl)‐1,4,7,10‐tetraazacyclododecan‐1‐yl]acetic acid (H₇DOA3P) and of the complexes [Ln(DOA3P)]^4? (Ln=Ce, Pr, Sm, Eu, and Yb) have been determined by multinuclear NMR spectroscopy in the range pD 2–13.8, without control of ionic strength. Seven out of eleven protonation steps were detected (pK =13.66, 12.11, 7.19, 6.15, 5.77, 2.99, and 1.99), and the values found compare well with the ones recently determined by potentiometry for H₇DOA3P, and for other related ligands. The overall basicity of H₇DOA3P is higher than that of H₄DOTA and trans‐H₆DO2A2P but lower than that of H₈DOTP. Based on multinuclear‐NMR spectroscopy, the protonation sequence for H₇DOA3P was also tentatively assigned. Three protonation constants (pK_MHL, pK_MH2L, and pK_MH3L) were determined for the lanthanide complexes, and the values found are relatively high, although lower than the protonation constants of the related ligand (pK , pK , and pK ), indicating that the coordinated phosphonate groups in these complexes are protonated. The acid‐assisted dissociation of [Ln(DOA3P)]^4? (Ln=Ce, Eu), in the region c_H+=0.05–3.00 mol dm^?3 and at different temperatures (25–60°), indicated that they have slightly the same kinetic inertness, being the [Eu(H₂O)₉]³⁺ aqua ion the final product for europium. The rates of complex formation for [Ln(DOA3P)]^4? (Ln=Ce, Eu) were studied by UV/VIS spectroscopy in the pH range 5.6–6.8. The reaction intermediate [Eu(DOA3P)]* as ‘out‐of‐cage’ complex contains four H₂O molecules, while the final product, [Eu(DOA3P)]^4?, does not contain any H₂O molecule, as proved by steady‐state/time‐resolved luminescence spectroscopy.     

Synthesis and Characterization of Guanidinium Difluoroiodate, [C(NH2)3]+[IF2O2]– and its Evaluation as an Ingredient in Agent Defeat Weapons‡

Ammonium and guanidinium difluoroiodate(V), [NH₄]⁺[IF₂O₂]^– ( 1a ) and [C(NH₂)₃]⁺[IF₂O₂]^– ( 1b ), and diazidoglyoxime, [N₃C=N–OH]₂ ( 2 ) were synthesized and the molecular structures in the solid state of 1b and 2 were elucidated by single‐crystal X‐ray diffraction. 1b : P$\bar{1}$ , a = 6.6890(5), b = 10.2880(6), c = 10.30.92(8) Å, α = 105.447(6), β = 108.568(7), γ = 91.051(5)°, V = 644.08(8) Å³, ρ = 2.650 g · cm^–3; 2 : P2₁/n, a = 4.4211(3), b = 13.7797(9), c = 4.9750(3) Å, β = 98.735(6), V = 299.57(3) Å³, ρ = 1.886 g · cm^–3. The suitability of compounds 1a and 1b as active ingredients for agent defeat weapons (ADW) with biocidal activity has been shown in detonation tests using geobacillus stearothermophilus spores. In addition, a complete energetic characterization of the promising primary explosive 2 is given.     

Crystal Structure,Synthesis, and Properties of tri‐Calcium di‐Citrate tetra‐Hydrate [Ca3(C6H5O7)2(H2O)2]·2H2O

From hydrothermal synthesis needle‐shaped crystals of [Ca₃(C₆H₅O₇)₂(H₂O)₂] · 2H₂O were obtained. The crystal structure was determined by single‐crystal X‐ray experiments and confirmed by powder data (P$\bar{1}$ (no. 2) a = 5.9466(4), b = 10.2247(8), c = 16.6496(13) Å, α = 72.213(7)°, β = 79.718(7)°, γ = 89.791(6)°, V = 947.06(13) Å³, Z = 2, R1 = 0.0426, wR2 = 0.1037). The structure was obtained from pseudo merohedrically polysynthetic twinned crystals using a combined data collection approach and refinement processes. The observed three‐dimensional network is dominated by eightfold coordinated Ca²⁺ cations linked by citrate anions and hydrogen bonds between two non‐coordinating crystal water molecules and two coordinating water molecules.     

AlCl3 · 3NH3 — eine Verbindung mit der Kristallstruktur eines Tetraammindichloroaluminium-diammintetrachloroaluminats: [AlCl2(NH3)4]+[AlCl4(NH3)2]−

AlCl₃ · 3NH₃ — a Compound with the Crystal Structure of a Tetraammine Dichloro Aluminium-Diammine Tetrachloro Aluminate: [AlCl₂(NH₃)₄]⁺[AlCl₄(NH₃)₂]^? . AlCl₃ · 3 NH₃ ? [AlCl₂(NH₃)₄]⁺ [AlCl₄(NH₃)₂]^? forms during the reaction of two mole NH₃ with AlCl₃(NH₃) at T ≥ 200°C. Repeated heating and cooling within 48 h between 200°C and 250°C gives a homogeneous product with total uptake of the necessary amount of NH₃. Slow sublimation in a vacuum line apparatus at 200°C gives crystals of the triammoniate sufficient for a X-ray structure determination: The compound contains elongated [AlCl₂(NH₃)₄]⁺ octahedra and compressed [AlCl₄(NH₃)₂]^? octahedra. Besides ionic bonding hydrogen bridge bonds with 3.369 Å ? d(N—H … Cl) ? 3.589 Å stabilize the atomic arrangement.     

Asymmetric salt effects on anion/cation reactions: A comparative study of the [Fe(CN)6]4− + [Co(NH3)5pz]3+ and [Ru(NH3)5pz]2+ + [Co(C2O4)3]3− reactions

The kinetics of electron transfer reactions between [Fe(CN)₆]^4? and [Co(NH₃)₅pz]³⁺ and between [Ru(NH₃)₅pz]²⁺ and [Co(C₂O₄)₃]^3? was studied in concentrated salt solutions (Na₂SO₄, LiNO₃, and Ca(NO₃)₂). An analysis of the experimental kinetic data, k_obs, permits us to obtain the true (unimolecular) electron transfer rate constants corresponding to the true electron transfer process (precursor complex → successor complex), k_et. The variations of both, k_obs and k_et, with salt concentrations are opposite for these reactions. These opposite tendencies can be rationalized by using the Marcus–Hush treatment for electron transfer reactions. The conclusion is that the negative salt effect found for the first reaction ([Fe(CN)₆]^4? + [Co(NH₃)₅pz]³⁺) is due to the increase of the reaction and reorganization free energies when the concentration of salt increases. In the case of the second reaction ([Ru(NH₃)₅pz]²⁺ + [Co(C₂O₄)₃]^3?), the positive salt effect observed is caused by the fact that the driving force becomes more favorable when the concentration of salt increases. Thus, it is shown that for anion/cation electron transfer reactions the kinetic salt effect depends on the charge sign of the oxidant (and the reductant). © 2004 Wiley Periodicals, Inc. Int J Chem Kinet 37: 81–89, 2005     

Synthese und Kristallstruktur von Mangan(II)‐ und Zinkamid,Mn(NH2)2 und Zn(NH2)2

Synthesis and Crystal Structure of Manganese(II) and Zinc Amides, Mn(NH₂)₂ and Zn(NH₂)₂ Metal powders of manganese resp. zinc react with supercritical ammonia in autoclaves in the presence of a mineralizer Na₂Mn(NH₂)₄ resp. Na₂Zn(NH₂)₄_.0.5NH₃ to well crystallized ruby‐red Mn(NH₂)₂ (p(NH₃) = 100 bar, T = 130°C, 10 d) resp. colourless Zn(NH₂)₂ (p(NH₃) = 3.8 kbar, T = 250°C, 60 d). The structures including all H‐positions were solved by x‐ray single crystal data: Mn(NH₂)₂: I4₁/acd, Z = 32, a = 10.185(6) Å, c = 20.349(7) Å, N(F_o) with F > 3σ (F) = 313, N(parameter) = 45, R/R_w = 0.038/0.043. Zn(NH₂)₂: I4₁/acd, Z = 32, a = 9.973(3) Å, c = 19.644(5) Å, N(F_o) with F > 3σ (F) = 489, N(parameter) = 45, R/R_w = 0.038/0.043. Both compounds crystallize isotypic with Mg(NH₂)₂ [1] resp. Be(NH₂)₂ [2]. Nitrogen of the amide ions is distorted cubic close packed. One quarter of tetrahedral voids is occupied by Mn²⁺‐ resp. Zn²⁺‐ions in such an ordered way that units M₄(NH₂)₆(NH₂)_4/2 occur. The H‐atoms of the anions have such an orientation that the distance to neighboured cations is optimum.     

[(C6H10)(NH3)2][Ni(H2O)4C6H2(COO)4]·4H2O – A Coordination Polymer with the Chain‐like Polyanion {Ni(H2O)4[C6H2(COO)4]2−}n

Triclinic single crystals of [(C₆H₁₀)(NH₃)₂][Ni(H₂O)₄C₆H₂(COO)₄]·4H₂O have been prepared in aqueous solution at 55 °C. Space group (Nr. 2), a = 691.23(6), b = 924.84(5), c = 1082.43(7) pm, α = 74.208(6)°, β = 75.558(7)°, γ = 68.251(6)°, V = 0.60985(7) nm³, Z = 1. The Nickel(II) species, located on a crystallographic inversion centre, is coordinated in a trans‐octahedral fashion by two oxygen atoms stemming from the centrosymmetric pyromellitate anions and four from water molecules (Ni–O 205.82(12) – 208.11(13) pm). The connection between Ni²⁺ and [C₆H₂(COO)₄)]^4? leads to infinite chain‐like polyanions extending parallel to with {Ni(H₂O)₄[C₆H₂(COO)₄]^2?}_n composition. [(C₆H₁₀)(NH₃)₂]²⁺‐cations are accomodated between the chains, compensating for the negative charge of the polyanions. Thermogravimetric analysis in air showed that the loss of water of crystallisation occurs in two steps between 102 and 206 °C, corresponding to the loss of 6 and 2 water molecules per formula unit, respectively. The dehydrated sample was stable between 206 and 353 °C. Further decomposition yielded nickel(II) oxide (NiO).     

Double complexes [Co(NH3)5(H2O)]2[Zr3F18]·6H2O and [Co(NH3)6]2[Zr3F18]·6H2O

The structures of orthorhombic bis[pentaammineaquacobalt(III)] tetra‐μ₂‐fluorido‐tetradecafluoridotrizirconium(IV) hexahydrate (space group Ibam), [Co(NH₃)₅(H₂O)]₂[Zr₃F₁₈]·6H₂O, (I), and bis[hexaamminecobalt(III)] tetra‐μ₂‐fluorido‐tetradecafluoridotrizirconium(IV) hexahydrate (space group Pnna), [Co(NH₃)₆]₂[Zr₃F₁₈]·6H₂O, (II), consist of complex [Co(NH₃)_x(H₂O)_y]³⁺ cations with either m [in (I)] or and 2 [in (II)] symmetry, [Zr₃F₁₈]⁶⁻ anionic chains located on sites with 222 [in (I)] or 2 [in (II)] symmetry, and water molecules.     

Effects of mixed H2O‐CH3CN solvents on the rate of hydrazinolysis of N‐phenylphthalimide: Spectral and kinetic evidence for the occurrence of N‐aminophthalimide on the reaction path

Kinetic study on the cleavage of N‐phenylphthalimide (NPhPT) in the presence of 0.05 M NH₂NH₂ and mixed H₂O‐CH₃CN solvents reveals the occurrence of reaction scheme where A, B, C, C₁, An, E, and F represent NPhPT, o‐CO^?₂C₆H₄CONHC₆H₅, o‐CONHNH₂C₆H₄‐ CONHC₆H₅, N‐aminophthalimide, aniline, o‐CO^?₂C₆H₄CONHNH₂, and o‐CONHNH₂C₆H₄‐CONHNH₂, respectively. But, in the presence of either nonbuffered ?0.20 M NH₂NH₂ hydrazine buffer of pH ～7.30–8.26 with total buffer concentration ([Buf]_T) of >0.02 M, further conversion of F to 2,3‐dihydrophthalazine‐1,4‐dione (DHPD) has been detected depending upon the length of the reaction time (t), the values of [Buf]_T, and pH. It has been shown that the rate of conversion of C₁ to F is much faster than that of C to C₁ which is much faster than that of F to DHPD. The reaction step A → C involves general base (GB) catalysis, while step C → C₁ seems to involve specific base–general acid (GA) and GB‐GB catalysis. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 37: 147–161, 2005     

Zur Reaktivität der Ferriophosphaalkene [(η5‐C5Me5)(CO)2FeP=C(NR)R2] (NR = NMe2, NC5H10, R2 = Ph,tBu) gegenüber Protonsäuren,Alkylierungsmitteln und [{(Z)‐Cycloocten}Cr(CO)5]

Transition Metal‐substituted Phosphaalkenes. 42 Reactivity of the Ferriophosphaalkenes [(η⁵‐C₅Me₅)(CO)₂FeP=C(NR )R²] (NR = NMe₂, NC₅H₁₀, R² = Ph, t Bu) towards Protic Acids, Alkylation Reagents, and [{( Z )‐Cyclooctene}Cr(CO)₅] The reaction of equimolar amounts of [(η⁵‐C₅Me₅)(CO)₂FeP=C(NR )R²] ( 2 a : NR = NMe₂, R² = Ph; 2 b : NMe₂. tBu; 2 c : NC₅H₁₀, Ph) and etherial HBF₄ gave rise to the formation of [(η⁵‐C₅Me₅)(CO)₂FeP(H)C(NR )R²] (BF₄) ( 3 a – c ) which were isolated as light red powders. Compounds 2 a – c were converted into [(η⁵‐C₅Me₅)(CO)₂FeP(Me)C(NR )R²] (SO₃CF₃) ( 4 a – c ) by treatment with methyl trifluoromethane sulfonate. In addition 2 a and Me₃SiCH₂OSO₂CF₃ afforded light red [(η⁵‐C₅Me₅)(CO)₂FeP(CH₂SiMe₃)C(NMe₂)Ph](SO₃CF₃) ( 5 ). The black complex [(η⁵‐C₅Me₅)(CO)₂FeP{Cr(CO)₅}C(NMe₂)Ph] ( 6 ) resulted from the combination of 2 a with [{(Z)‐cyclooctene}Cr(CO)₅]. The novel products were characterized by elemental analyses and spectra (IR, ¹H‐, ¹³C‐ und ³¹P‐NMR).