Presence Of NaBPh4 Research Articles

Cationic Bis- and Tris(η2-(pyrazol-1-yl)methane) Acetyl Complexes of Iron(II) and Ruthenium(II): Synthesis, Characterization, Reactivity, and Interionic Solution Structure by NOESY NMR Spectroscopy

The complexes trans,cis-M(PMe3)2(CO)2(Me)I (M = Fe and Ru, 1a,b) react with bis- and tris(pyrazol-1-yl)methane, in the presence of NaBPh4, affording trans-[M(PMe3)2(CO)(COMe)(pz2-CH2)]BPh4 (2a,b) and trans-[M(PMe3)2(CO)(COMe)(η2-pz3-CH)]BPh4 (3a,b), respectively (pz = pyrazolyl ring). The reactions of 1b with 5,5‘-Me2-pz2-CH2 and 3,5‘-Me2-pz2-CH2 produce trans-[Ru(PMe3)2(CO)(COMe)(5,5‘-Me2-pz2-CH2)]BPh4 (4) and trans-[Ru(PMe3)2(CO)(COMe)(3,5‘-Me2-pz2-CH2)]BPh4 (5), respectively. A mixture of trans,cis-[Ru(PMe3)2(CO)2(η1-3,3‘-Me2-pz2-CH2)(Me)]BPh4 (6) and trans-[Ru(PMe3)2(CO)(COMe)(3,3‘-Me2-pz2-CH2)]BPh4 (7) is obtained from reaction of 1b and 3,3‘-Me2-pz2-CH2. The reactions of 2−7 with nucleophiles either give back the starting complex (Nu = I-) or analogous complexes (Nu = Br- and Cl-) or produce decomposition products of the complexes (Nu = I2, Br2, Cl2, and OMe-). The solid state structures of 2b and 3b were obtained using single-crystal X-ray diffraction. For all complexes, 2−7 as well as complex 8 (analogue to 2a, having a BF4- counterion instead of BPh4-), the ion-pair structures and the localization of the counterion in solution with respect to the organometallic moiety were investigated by the detection of interionic contacts in the 1H-NOESY and 19F{1H}-HOESY NMR spectra.

Phosphinomethanides and Group 15 element halides: Redox reactions, rearrangements and novel heterocycles

The reactions of ECl 3 (E = P, As, Sb, Bi), RPCl 2 (R = Me, Ph, tBu, Cy 2N) and Ph 2PCl, respectively, with ambident lithium phosphinomethanides are described. The reaction with LiCH 2PMe 2, 1, by E C bond formation, leads to the substitution products E(CH 2PMe 2) 3, 2a–d, (E = P, As, Sb, Bi) and R—P(CH 2PMe 2) 2 (R = Me, Ph, tBu, Cy 2N) 5a–d. In contrast, LiC(PMe 2)(SiMe 3) 2 · 0.5TMEDA, 6, gives substitution products with ECl 3 (E = P, As, Sb), by E P bond formation. Thus, the first element—tris(P—ylide)derivatives E(PMe 2 C(SiMe 3) 2) 3, 7a–c, are obtained. 7b is characterized by X-ray structure determination. In these reactions, oxidative P P coupling to give [(Me 3Si) 2C PMe 2] 2, 8, is also observed, and exclusively in the reaction of BiCl 3 with 6. The reaction of RPCl 2 (R = Me, Ph, tBu, Cy 2N) with 6 strongly is dependent on the nature of R. For R = Me, only substitution is observed, yielding Me P(PMe 2 C(SiMe 3) 2) 2, 10, while for R = Ph, both substitution and Li/Cl exchange with subsequent formation of 8 and the diphosphane [(Me 3Si) 2C PMe 2 PPh] 2, 12, are found. The latter has been characterized structurally. In contrast, for R = tBu, only ( tBuP) 3, 13, and ( tBuP) 4, 14, are obtained. An analogous result is observed in the reaction of tBuPCl 2 with LiC(PMe 2) 2(SiMe 3), 17. The reaction of Cy 2NPCl 2 with two equivalents of LiC(PMe 2)(SiMe 3) 2·0.5TMEDA, 6, gives a phospha-alkene Cy 2N P C(SiMe 3) 2, 16, and the substitution product Cy 2N P(PMe 2 C(SiMe 3) 2) 2, 15. Likewise, LiC(PMe 2) 2(SiMe 3), 17, reacts with PhPCl 2 to give the substitution product Ph P(PMe 2 C(PMe 2)(SiMe 3)) 2, 18, which is characterized by X-ray structure determination, whereas with MePCl 2 only the P—ylide Me 2P PMe 2 C(PMe 2)(SiMe 3), 20, and the coupling product [(Me 2P)(Me 3Si)C PMe 2] 2, 19, are formed. The latter is also obtained in the reactions of BiCl 3 or SbCl 3 with LiC(PMe 2) 2(SiMe 3), 17. Analogous redox reactions with AsCl 3 and PCl 3, respectively, lead to the bis-pentacyclic μ-[C(PMe 2) 2(SiMe 3)]As 2 2, 21, and the hexacycle P − PMe 2 − C(SiMe 3 ) − PMe 2 − C(SiMe 3 ) − ⎴ PMe 2 , 22, which were structurally characterized by X-ray analyses. Depending on the reaction conditions, the reaction of PCl 3 with LiC(PMe 2) 2(SiMe 3), 17, alternatively may lead to the triphosphete P − PMe 2 − C(SiMe 3 ) − ⎴ PMe 2 , 24. By using P—phenyl-substituents instead of P—methyl-substituents, i.e. in the reaction of LiC(PPh 2) 2(SiMe 3), 25, with PCl 3 or AsCl 3, the triphosphete P − PPh 2 − C(SiMe 3 ) − ⎴ PPh 2 , 26a, or its arsenic analogue As − PPh 2 − C(SiMe 3 ) − ⎴ PPh 2 , 26b, are respectively formed, along with the chlorine substituted ylide (Cl)(Ph) 2P C(PPh 2)(SiMe 3), 27. 26a,b are characterized by X-ray structure determinations. The synthesis of the first ten-electron phosphorus cation P[C(PPh 2) 2(SiMe 3)] 2 +, 30, with a homonuclear, spirocyclic PP 4-framework was achieved by reacting the triphosphete 26a with the ylide 27 in the presence of NaBPh 4. The crystal structure of the cation of 30, which adopts a Ψ-tbp geometry, was determined.

BINDING OF 2-(2-ARYLTELLUROETHYL)PYRIDINES WITH Cu AND Co

Abstract 2-(2-Aryltelluroethyl)pyridine(L) complexes of copper(I) and cobalt(II), [Cu(L)(μ-Br)2Cu(L)] and [CoBr2(L)], have been synthesized by reaction of the ligand with anhydrous metal bromides in nitromethane under a dinitrogen atmosphere. The same reaction in the presence of NaBPh4, excess ligand and air led to the oxidation of metals and formation of the complexes [Cu(L)(μ-Br)2Cu(L)](BPh4)2 and [CoBr2(L)2](BPh4). All complexes have been characterized by elemental analyses, molecular weight and molar conductance measurements, magnetic moments and spectroscopy (IR, electronic, 1H and 125Te NMR).

Ligandeneffekte bei der Synthese der Komplexe C1Rh [formula omitted] (P ≈ O), [Rh [formula omitted]2][BPh 4] und [Rh(COD)( [formula omitted])][BPh 4

The behaviour of the rhodium(I) complexes [(μ-Cl)Rh(COE) 2] 2 ( 1, COE = cyclooctene) and [(μ-CI)Rh(COD)] 2 ( 6, COD = 1,5-cyclooctadiene) towards a series of ether-phosphines of the R 2 PCH 2 CH 2OCH 3 (R = tBu ( 2a), iPr ( 2b), Cy ( 2c), Ph ( 2d)) was examined. Complex 1 reacts with 2b,c to give pure RhCI( P O )(P ≈ O) ( 4b,c, P O : η 2-bonded O,P ligand; P ≈ O: η 1-P-bonded O,P ligand). In contrast, treatment of 1 with 2d predominantly yields [(μ-Cl)Rh(P ≈ O) 2] 2 ( 3d), which may be photochemically converted into 4d. In the presence of NaBPh 4, the reaction of 1 with 2b,c results in the formation of the bis(chelate) complex cis-[Rh( P O ) 2][BPh 4] ( 5b,c). 5d, however, is only accessible by Cl − abstraction from 4d. Treatment of 6 with 2a–c and NaBPh 4 affords [(COD)Rh( P O )[BPh 4] ( 7a–c), whereas 2d gives [(COD)Rh(P ≈ O) 2][BPh 4] ( 8d).

Effect of ion-pairs on the stereochemistry of decarbonylation of acetyl iodide complexes of ruthenium: Evidence of anion catalysis in the CO insertion

Decarbonylation of cis,trans-[Ru( 13CO a)(CO b)(PMe 3) 2(COMe)I] ( 2) in the presence of NaBPh 4 is stereospecific and gives [Ru(CO a)(CO b)( 13CO b)(PMe 3) 2Me] + ( 3) ( a and b indicate CO trans or cis, respectively, to the methyl or the acetyl group); by the principle of microscopic reversibility this demonstrates that the inverse process of insertion is catalysed by anions.

Dechlorination of ClPEt 2 by (np 3)Pt(PPh 3) (np 3N(CH 2CH 2PPh 2) 3): synthesis and characterization of [(np 3)Pt(PEt 2)](BPh 4) and [(np 3)Pt(PHEt 2)](BPh 4) 2

The platinum(O) complex (np 3)Pt(PPh 3) (np 3N(CH 2CH 2PPh 2) 3), undergoes oxidative addition by ClPEt 2, in the presence of NaBPh 4, to yield the five-coordinate terminal phosphide [(np 3)Pt(PEt 2)](BPh 4). When the solvated compound (np 3)Pt(PPh 3)·0.4CH 3CH 2CH 2CH 2OH is used as starting material, [(np 3)Pt(PHEt 2)](BPh 4) 2 is formed by reaction of the phosphide with HCl released by alcoholysis of CIPEt 2. The related complex [(pp 3)Pt(PEt 2)](BPh 4)(pp 3{P(CH 2CH 2PPh 2) 3}) has been prepared by deprotonation of [(pp 3)Pt(PHEt 2)](BPh 4) 2, for comparison purposes. The complexes have been characterized by elemental analyses, conductibility measurements and 1H and 31P NMR spectra. The X-ray structural analysis of [(np 3)Pt(PHEt 2)](BPh 4) 2 has been carried out.

Heteropolymetallic complexes of 1,1′-bis(diphenylphosphino)ferrocene (dppf): VI. Synthesis and crystal structure of [Rh(dppf)(η 6-C 6H 5B(C 6H 5) 3

The complex [Rh(COD)(dppf)]ClO 4 (COD = 1,5-cyclooctadiene; dppf = Fe((η 5-C 5H 4)P(C 6H 5) 2) 2) has been prepared by removal of the chloride ligand from [RhCl(COD)] 2 by AgClO 4 in acetone, followed by addition of one equivalent of 1,1′-bis(diphenylphosphino)ferrocene. Reaction of [Rh(COD)(dppf)]ClO 4 with dihydrogen in the presence of NaBPh 4 affords the neutral complex [Rh(dppf)(η 6-C 6H 5)B(C 6H 5) 3], which has been characterized by single crystal X-ray analysis. The Rh(dppf) + ion interacts strongly with the tetraphenylborate anion, one of the C 6C 5 groups being η 6-coordinated to the metal. The plane defined by the two P atoms of the chelated bisphosphine and the Rh atom is almost perpendicular to the mean plane containing the η 6-bonded phenyl group. The 1H and 31P NMR spectra of the isolated complexes are also discussed

Reactions of the A-frame-like monocarbonyl complexes Re 2(μ-X)(μ-dppm) 2X 3(CO) (X = Cl or Br; dppm = Ph 2PCH 2PPh 2) with trimethylphosphine and trialkylphosphite ligands. The structural characterization of [Re 2(μ-Cl)(μ-CO)(μ-dppm) 2Cl 2(PMe 3) 2]Cl

The 1:1 carbonyl adduct Re 2Cl 4(dppm) 2(CO) reacts with PMe 3 in CH 2Cl 2 at room temperature to afford the green diamagnetic complex [Re 2Cl 3(dppm) 2(CO)(PMe 3) 2]Cl. When similar reactions are carried out in the presence of NaBPh 4 or TlPF 6, with THF or CH 2Cl 2 as the reaction solvents, respectively, the salts [Re 2Cl 3(dppm) 2(CO)(PMe 3) 2]X (X = BPh 4 or PF 6) are produced. Similar procedures have been used to prepare the bromo-derivative [Re 2Br 3(dppm) 2(CO)(PMe 3) 2]PF 6, and the phosphite complexes {Re 2Cl 3(dppm) 2(CO)[P(OR) 3] 2}PF 6 (R = Me or Et). IR spectroscopy shows that the CO ligand is bridging the two metal centres (ν(CO) ca 1635 cm −1 for the PMe 3 complexes and ca 1680 cm −1 for the P(OR) 3 derivatives). This conclusion has been confirmed by a crystal structure determination on [Re 2Cl 3(dppm) 2(CO)(PMe 3) 2]Cl·1/2CH 2Cl 2. The crystallographic data are as follows: triclinic space group P1̄, a = 13.261(1), b = 19.246(2), c = 11.860(2) Å, α = 97.57(1), β = 98.98(1), γ = 79.08(1)°, V = 2919(1) Å 3 and Z = 2. The structure was refined to R = 0.043 ( R w = 0.056) for 5949 data with I > 3.0σ( I). The dirhenium cation has the structure of an edge-shared bioctahedron with virtual C 2ν symmetry. There is a trans disposition of bridging dppm ligands. The equatorial plane contains a bridging carbonyl and a bridging chloride ligand. The three chloride ligands are in an all- cis arrangement to one another on one side of this plane; the two PMe 3 ligands are cis to the μ-CO ligand. The ReRe distance is 2.602(1) Å.

Preparation and structural studies of diphenylthiophosphinito rhodium(III) complexes. X-ray structure analysis of [{(C5Me5)Rh}2(µ-Cl)2(µ-Ph2PS)][BPh4

The tri-µ-hydroxo-dirhodium complex [{(C5Me5)Rh}2(µ-OH)3][ClO4](1) reacts with the appropriate amount of Ph2P(S)H, in acetone, to give [{(C5Me5)Rh}2(µ-OH)n(µ-Ph2PS)3–n][ClO4][n= O(2) or 1(3)]. Reaction of complex (1) with an equimolar amount of Ph2P(S)H, in methanol gave the di-µ-methoxo-µ-diphenylthiophosphinito complex [{(C5Me5)Rh}2(µ-OMe)(2(µPh2PS)][ClO4](5). The mixed-bridged complex [{(C5Me5)Rh}2(µ-OMe)(µ-pz)(µ-Ph2PS)][ClO4](6)(pz = pyrazolate) was obtained by addition of Ph2P(S)H to a methanolic solution of [{(C5Me5)Rh}2(µ-OH)(µ- pz)2]-[ClO4]. The complexes (5) and [{(C5Me5)Rh}2(µ-OH)(µ-Ph2PS)2][ClO4](3) react with HCl yielding the binuclear chloride compounds [{(C5Me5) Rh}2(µ-Cl)2(µ-Ph2PS)][ClO4](7) and [{(C5Me5)Rh}2(µ-Cl)(µ-Ph2PS)2][ClO4](9). The doubly homo-bridged complex [{(C5Me5)-Rh(ButNC)}2(µ-Ph2PS)2][ClO4], (10) can be prepared from [(C5Me5) Rh(acac)(ButNC)][ClO4](acac = acetylacetonate ion) and an equimolar amount of Ph2P(S)H. The mononuclear species [(C5Me5)Rh(acac)Cl] reacts with an equimolar amount of Ph2P(S)H in the presence of NaBPh4 giving the binuclear complex [{(C5Me5)Rh}2(µ-Cl)(µ-Ph2PS)2][BPh4](11). Its n.m.r. spectra show the presence of two isomers. Reaction of [{(C5Me5)RhCl}2(µ-Cl)2] with Ph2P(S)H and KOH yields the mononuclear complex [(C5Me5)Rh(Ph2PS-P)(Ph2PS-PS)](12). This compound is converted by sulphur-atom abstraction into [(C5Me5)Rh(Ph2PS-P)(Ph2PS2-SS)](13). The X-ray structure analysis of [{(C5Me5)Rh}2(µ-Cl)2(µ-Ph2PS)][BPh4](8) is also reported: the crystals are triclinic, space group P, and have been refined to R 0.035 and R′ 0.038. The rhodium–rhodium distance is 3.570 1(5)A.

Trimethylphosphine-cobalt(I) complexes. crystal and molecular structure of the (nonbornadiene)tris(trimethylphosphine)cobalt(I) tetraphenylborate complex, [Co(η 4-C 7H 8)(PMe 3) 3[BPh 4

Reaction of CoBr(PMe 3) 3 with norbornadiene, a non-conjugated diene, in presence of NaBPh 4 gives rise to a high yield of the [Co(η 4-C 7H 8)(PMe 3) 3]BPh 4 complex. Its cyrstal structure has been determined by X-ray diffraction techniques. The compound belongs to the orthorhombic space group Pmn2 1, with a 15.114(11), b 10.006(7), c 12.316(11) Å) and Z  2 formula units per cell. The structure was solved from a set of 1482 nonzero Mo- K α reflections collected at 170 K and refined to R  0.047. The crystal consists of discrete BPh 4 − anions and [Co(PMe 3) 3− (norbornadiene)] + cations. The BPh 4 − ion sits on the crystallographic mirror plane and it is not disordered. The complex cation is involved in a two-fold disorder in which two individuals are related by the crystallographic mirror plane. In addition, one of the phosphines shows two-fold oreientation disorder of the methyl groups about the CoP bond. The complex cation has no crystallographic symmetry of its own. Its environment is best described as a distorted square pyramid (mean L apicalCoL basal 103.6°), with one of the PMe 3 Ligands (CoP(1) 2.290(3) Å) occupying the apical position. Norbornadiene spans two adjacent basal sites (Comid |2.010(10) and 1.935(11) Å), whereas the two remaining basal sites are occupied by PMe 3 molecules (CoP(2) 2.243(2), CoP(3) 2.182(3) Å). Multinuclear NMR studies (183–293 K) show that the complex is stereochemically non-rigid in this temperature range.

Insertion reactions of 1,4-diisocyanobenzene in binuclear Pd(I) complexes

Reactions between XPd(μ-dmp) 2PdX′ (X = X′ = Cl, Br, I, NCO, SCN, N 3 or C 6F 5; X = C 6F 5, X′ = Cl, Br, I, NCO) with 1,4-diisocyanobenzene lead to the tetranuclear complexes [(μ,μ′-CNC 6H 4NC){XPd(μ-dpm) 2PdX′} 2], where both ends of the diisocyanide are inserted in a metalmetal bond. The cationic derivatives [(μ,μ′-CNC 6H 4NC){(RNC)Pd(μ-dpm) 2(CNR)} 2](BPh 4) 4 and [(μ,μ′-CNC 6H 4NC){(RNC)Pd(μ-dpm) 2Pd(C 6F 5)} 2] (BPh 4) 2 (R = p-Tol, Cy, or tBu) are obtained by reacting [(μ,μ′-CNC 6H 4NC){ClPd(μ-dpm) 2PdX} 2] (X= Cl or C 6F 5) with RNC in the presence of NaBPh 4. Treatment of [(μ,μ′-CNC 6H 4NC){ClPd(μ-dpm) 2Pd(C 6F 5)}] 2 with NaBPh 4 causes the di-insertion and subsequent coordination of the isocyanide, yielding [(C 6F 5)Pd(CN-C 6H 4NC) Pd(μ-dpm) 2Pd(C 6F 5)](BPh 4) 2.

Synthesis of neutral and cationic pentafluorophenylpalladium(I) derivatives. Insertion versus coordination of isocyanides in binuclear palladium(I) complexes

Reaction between PdX(C6F5)(dpm)2 (dpm = bis(diphenylphosphino)methane; X = Cl, Br, I, CNO or C6F5) and Pd2(dba)3CHCl3 (dba = dibenzylideneacetone) gives, the pentafluorophenyl palladium(I) derivatives [XPd(μ-dpm)2Pd(C6F5)]. Treatment of [ClPd(μ-dpm)2Pd(C6F5)] with an excess of the ligand L, and in the presence of NaBPh4 gives the cationic complexes [LPd(μ-dpm)2Pd(C6F5)]BPh4 (L = PPh3, P(OPh)3, pyridine or tetrahydrothiophene (tht)). Reaction with isocyanides RNC leads to three different types of compounds: (a) products with the isocyanide groups inserted into the PdPd bond [(μ-RNC){;XPd(μ-dpm)2Pd(C6F5)};] (X = C6F5; R = p-tolyl; X = Cl, R = p-tolyl or Cy); (b) cationic complexes with terminal isocyanides [(RNC)Pd(μ-dpm)2Pd(C6F5)]X (X = Cl; R = t-Bu; X = BPh4, R = p-tolyl, Cy or t-Bu) and (c) complexes which contain both bridging and terminal isocyanides, [(μ-RNC){;(RNC)Pd(μ-dpm)2Pd(C6F5};BPh4] (R = p-tolyl or cyclohexyl). Addition of NaBPh4 to solutions of complexes of type a (X = Cl) results in deinsertion of the isocyanide to give complexes of type b. IR spectroscopy reveals that [(μ-CyNC){;ClPd(μ-dpm)2Pd(C6F5)};] isomerizes in CH2Cl2 to give [(CyNC)Pd(μ-dpm)2pd(C6F5)]Cl, which upon recrystallization regenerates the former complex, showing that in this case the insertion-deinsertion process is reversible.

Diphenylacetylene as a variable electron donor: syntheses and X-ray crystal structures of [Co(C2Ph2)(MeCN)(PMe3)3]BPh4 and [Co(C2Ph2)(PMe3)3]BPh4

Two cationic cobalt(I) complexes were prepared as their BPh4-salts by the reaction of diphenylacetylene with CoBr(PMe3)3 in the presence of NaBPh4; diphenylacetylene behaves as a 2-electron donor in [Co(C2Ph2)(MeCN)(PMe3)3]BPh4 isolated from acetone–acetonitrile mixtures, but as a 4-electron donor in [Co(C2Ph2)(PMe3)3]BPh4 obtained from acetone.

Trinuclear palladium(II) complexes with triply-bridging sulfide ligands

The complexes [(PMe 3) 6Pd 3(μ-S) 2](BPh 4) ( 4) and [(PMePh 2) 6Pd 3(μ-S) 2](BPh 4) 2 ( 6) are formed from [Pd(CH 3CN) 4](BF 4) 2 ( 5), H 2S and the corresponding phosphine in presence of NaBPh 4. Complex 4 is also obtained, although in low yields, as a secondary product in the reaction of [(PMe 3) 3PdH]BPh 4 with COS. 4 crystallizes in the space group P2 1/c (Z = 4) with a = 1551(2), b = 2517(7), b = 2517(7), c = 1830(3) pm and β = 94.74(9)°. The palladium and sulfur atoms of the dication [(PMe 3) 6Pd 3S 2] 2+ form a slightly distorted trigonal bipyramid in which one of the PdPd distances is significantly shorter than the other two. The coordination sphere around each palladium atom is nearly square-planar with angles SPdS = 79.3, PPdP = 97.4 and SPdP = 91.6° (mean values).

Reaction of carbonyl-stabilized selenonium ylides with derivatives of some group V trivalent elements

1. The “iodonium method” is an efficient way of synthesizing the selenonium ylides: 2-methylphenylselenuranylidenedimedon and methylphenylselenuranylidenedibenzoylmethane. 2. Similar to S-alkyl-substituted sulfonium ylides, 2-methylphenylselenuranylidenedimedon and methylphenylselenuraaylidenedibenzoylmethane when treated with Et3N or Ph3As in the presence of NaBPh4 are demethylated to give the corresponding ammonium and arsonium tetraphenylborates.

A series of hydridoplatinum(II) complexes stabilized with tribenzylphosphines: their preparation, and an empirical approach to the mutual influence of ligands

The preparation, IR and NMR spectra of 123 platinum hydrides of the general formula, trans-PtHX(PBz 3) 2 or trans-PtHL(PBz 3) 2BPh 4 (X = a uninegative anionic ligand, L = a neutral donor molecule, Bz = benzyl), are described. Neutral platinum hydrides have been synthesized by the reduction of trans-PtCl 2-(PBz 3) 2 with NaBH 4, by the Michaelis—Arbuzov rearrangement, or by metathesis. Cationic hydridoplatinum(II) complexes are obtained from the reaction of trans-PtHX(PBz 3) 2 (X = Cl or NO 3) with a donor molecule (L) in the presence of NaBPh 4, or by coordinating a donor molecule through use of PtH(PBz 3) 2BPh 4 · 1 2 CH 2Cl 2. The observed trends in ν(PtH), τ(H), 1 J(PtH) and 1 J(PtP) in a series of the hydridobenzylphosphineplatinum(II) complexes are discussed in terms of “ trans- or cis-influences”, defined as the ability of a ligand to weaken the bond trans or cis to itself. The data support the view that a donor atom trans to the hydridic ligand is important in determining the strength of the PtH bond in this series. Some remarks on the distinctive characteristics of some complexes, e.g., dissociation of coordinated cycloalkanone from platinum(II) or stereochemical non-rigidity of the sym-dimethylurea ligand, are included. Tricyclohexylphosphine analogs also have been prepared for comparison.

The chemistry of transition-metal nitrosyl compounds. Part VII. The preparation and study of some cationic nitrosyl complexes of iron

The cationic iron nitrosyl complexes [Fe(CO)2NOL2]PF6[L = P(OPh)3, P(OMe)3, PPh3, PMePh2, PMe2Ph, PEt3, P(C6H11)3, AsPh3 and 1/2dppe] have been prepared and some of their properties studied. Certain of these cations [L = P(OMe)3, PMePh2, and PMe2Ph] react with additional ligand (L) to produce the cationic species [Fe(CO)(NO)L3]+. With dppe the complex [Fe(CO)2NO(dppe)]PF6 yields the mononitrosyl cation [Fe(NO)(dppe)2]+; this cation has also been prepared from the reaction of the hydride FeHCl(dppe)2 with N-methyl-N-nitrosotoluene-p-sulphonamide in the presence of NaBPh4. The cations [Fe(CO)2NOL2]+ react with OMe– to produce the neutral carboxy-compounds Fe(CO)(NO)(L)2CO2Me (L = PPh3 or 1/2dppe). No evidence for nucleophilic addition of OMe– to the co-ordinated NO group in any of the cationic species has been found.

Cationic complexes of iridium. Part I. The preparation and properties of some phosphine and arsine complexes

A series of cationic five-co-ordinate complexes of formula [Ir(CO)3L2]BPh4(I)(L = tertiary phosphine or arsine) have been prepared by passage of carbon monoxide through solutions of trans-[IrCl(CO)L2] in the presence of sodium tetraphenylborate. From these, the corresponding cationic dihydride complexes [IrH2(CO)2L2]BPh4(II) have been obtained by reaction with hydrogen under mild conditions. Some of the complexes (I) lose carbon monoxide reversibly to give stable four-co-ordinate complexes of formula [Ir(CO)2L2]BPh4(III). Addition of MeO2C·C⋮C·CO2Me (A) to (I) acetylene complexes of formula [Ir(A)(CO)2L2]BPh4. The hydride complex (II)(where L = PMePh2) reacts with π-bonding ligands L′(L′= CO, tertiary phosphines, phosphites, etc.) to give complexes of formula [Ir(CO)2(PMePh2)2L′]BPh4 which, for L′= PMePh2, reacts further with hydrogen to give [IrH2(CO)(PMePh2)3]BPh4. Reaction of trans-[IrCl(CO)(PMePh2)2] with tertiary phosphites, L′, in the presence of NaBPh4 gives complexes of formula [Ir(CO)(PMePh2)2L′2]BPh4. The i.r. and 1H n.m.r. spectra of the new complexes prepared are reported, and are used in making stereochemical assignments.