Chelating Fashion Research Articles

Synthesis and reactivity of N, N, N′, N′-tetramethyldiaminomethane complexes of tricarbonylrhenium(I). X-ray molecular structures of [ReBr(CO) 3(TMDM)] and [{Re(bipy)(CO) 3} 2(μ-OH)][SbF 6

N,N,N′ ,N′-Tetramethyldiaminomethane (TMDM) is known to act as a source of Me 2NCH in carbonyl substitution reactions, but the reaction of TMDM with the neutral halogenopentacarbonylrhenium(I) compounds gave unexpectedly fac-[ReX(CO) 3(TMDM)] (X=Cl, Br or I), in which the intact TMDM ligand acts in a chelating fashion. The complexes are stable both in the solid-state and in solution, but rapidly decompose on dehalogenation, yielding Re metal. Under anaerobic conditions, the reaction of TMDM with [Re(CO) 3(bipy)] + also leads to decomposition. In the presence of oxygen the system is stable. Three Re(bipy) containing species were identified in the reaction mixture: [{Re(CO) 3(bipy)} 2(μ-OH)][SbF 6] ( 1), which was characterised by X-ray crystallography, [{Re(CO) 3(bipy)} 2(μ-OH 2)][SbF 6] 2 ( 2) and [Re(OH)(CO) 3(bipy)] ( 3).

Bis(2-pyridylethyl)ammonium perchlorate

The title compound, C14H18N3+·ClO4−, a perchlorate salt of the monoprotonated form of bis(2-pyridyl­ethyl)­amine, has a structure in which one of the two H atoms on the amine N atom forms hydrogen bonds to the two pyridyl N atoms in a chelating fashion, while the second H atom on the amine is also used in hydrogen bonding to a perchlorate O atom.

Trimethylplatinum(IV) complexes of dithiocarbamato ligands: an experimental NMR study on the barrier to C–N bond rotation

The trimethylplatinum(IV) complexes of a number of dithiocarbamato ligands have been prepared. The complexes are dimeric in the solid-state and in solution, with the ligands acting in both a bridging and chelating fashion. Restricted rotation about the ligand C-N bonds in solution leads to the formation of four rotomers. The kinetics of the restricted rotation were measured by a variety of dynamic NMR techniques in the slow and intermediate exchange regimes. Two distinct processes are observed, namely the independent rotation about each C-N bond and correlated rotation about both C-N bonds. The free energies of activation, which are strongly dependent on the nature of the ligand substituents, are in the range 65 – 88 kJ mol-1 at 298 K. The origins of the barrier to rotation and the effects of the N substituents are discussed. The X-ray structures of fac-[PtMe3(Me2NCS2)]2 (2) and fac-[PtMe3(Ph(H)NCS2)]2 , (6) are reported.

Imino−Rhodium(III) and −Ruthenium(II) Compounds with Stereogenic Metal Centers

The synthesis and characterization of optically active imino complexes (RM or SM)-[(η5-C5Me5)RhCl(imine)][SbF6] (imine = Ln = N-(2-pyridylmethylene)-(R)-1-phenylethylamine (L1) (1a,a‘), N-(2-pyridylmethylene)-(R)-1-naphthylethylamine (L2) (2a,a‘), N-(2-pyridylmethylene)-(R)-1-cyclohexylethylamine (L3) (3a,a‘)) or [(η6-p-MeC6H4iPr)RuCl(imine)]A (A = SbF6, imine = L1 (4a,a‘), L2 (5a,a‘), L3 (6a,a‘), N-(2-pyridylmethylene)-(1R,2S,4R)-1-bornylamine) (L4) (7a,a‘); (A = BF4, imine = L1 (4b,b‘), L2 (5b,b‘), L3 (6b,b‘), L4 (7b,b‘)) is reported. The absolute crystal structures of the (RRh)-1a and (RRu)-7b epimers were determined by X-ray analysis. Both complexes possess a chiral metal center in a pseudo-octahedral environment, being bonded to an η5-C5Me5 group (1a) or to an (η6-p-MeC6H4iPr) ring (7b), a terminal chloride, and, in a chelating fashion, to the two nitrogen atoms of the imine ligand. At room temperature, in acetone or chloroform, the complexes are configurationally stable but in refluxing methanol epimerize at the metal center. Dichloromethane/acetone solutions of the solvate complexes [(ηn-ring)M(imine)S]2+ are active catalysts for the Diels−Alder reaction between methacrolein or acrolein and cyclopentadiene. The reaction occurs rapidly at room temperature and, in general, good exo/endo selectivities and moderate enantioselectivities are achieved.

Platinum(II) complexes with 1-amino-4-thiapentylphosphonic acid and its diethyl ester: Spectroscopic, electrospray mass spectrometric and X-ray studies

New platinum(II) complexes of 1-amino-4-thiapentylphosphonic acid and its diethyl ester were prepared and structurally characterised both in a solid state and in solution. The ligands coordinate to platinum(II) in the {N,S} chelating fashion yielding complexes of Pt(L)Cl 2 type. The crystal structure of the Pt(II) complex with diethyl 1-amino-4-thiapentylphosphonate was also determined.

Synthesis and metal complexes of a chelating ligand containing thiomorpholine and pyridine: 2,6-bis(thiomorpholinomethyl)pyridine

A chelating ligand, 2,6-bis(thiomorpholinomethyl)pyridine (L), was synthesised. Its palladium (II), copper(II) and nickel(II) complexes of the formula ML(NO 3) 2, (MPd, Cu and Ni), were prepared and characterised. The molecular structures of the three complexes were determined by X-ray diffraction. In all the compounds prepared the ligand acts in a tridentate fashion using its three N atoms while the two S atoms remain free. The Pd complex possesses a distorted square planar coordination geometry with one of the two nitrato groups coordinating as a unidentate ligand and the other ionic. The PdN (pyridine) bond length is 1.857(4) Å, which is believed to be the shortest PdN separation ever observed. In the Cu complex, the copper atom is five-coordinated in a distorted square planar arrangement with the two nitrato groups acting as unidentate ligands and occupying the apex and one equatorial position. The Ni complex has a distorted octahedral coordination sphere: one nitrato group behaves in a chelating fashion and the other unidentate.

Synthesis, Structure, and Reactivity of (C5H4SiMe3)2Y{(μ-FC6F4)(μ-Me)B(C6F5)2}: Tight Ion Pairing in a Cationic Lanthanide Complex

The reaction of [Cp‘2YMe]2 (Cp‘ = C5H5, C5H4SiMe3) with B(C6F5)3 affords the complexes Cp‘2Y{MeB(C6F5)3}. The anion is coordinated in a chelating fashion via one ortho-fluorine atom and agostic interactions to two of the methyl hydrogens; the complexes are highly fluxional in solution. They act as initiators for the carbocationic polymerization of isobutene.

Chemistry of Palladium and Platinum with Selenium and Tellurium Ligands

Reactions of NaER (E = Se, Te; R = Ph, substituted Ph or 2-pyridyl) with a number of mono- and bi-nuclear palladium and platinum complexes have been investigated. Complexes of the type [M(Sepy)2], [M(ER)2(PR3)2], [M2Cl2(μ-ER)2(PR3)2] and [M2Cl2(μ-Cl)(μ-ER)(PR3)2] (M = Pd, Pt) were isolated. They were characterized by elemental analysis, NMR (1H, 13C, 31P, 77Se, 125Te, 195Pt) data and in a few cases by X-ray diffraction studies. The [M(Sepy)2(PPh3)2] dissociates into PPh3 and [M(Sepy)(η2-Sepy)(PPh3)] in solution. 2-Selenopyridine in its complexes acts in a monodentate (bonding through selenium) as well as in chelating (Se⌢N) or bridging fashion. The mononuclear complexes [M(ER)2(PR3)2] are useful precursors for stepwise synthesis of cationic bi- and tri-nuclear derivatives.

Synthesis, Characterization and Some Properties of Oxoperoxo Complexes of Molybdenum with 2-Hydroxy-1-naphthaldehyde Isonicotinoylhydrazone

Abstract The peroxo complexes [MoO(O2) (ihnpy)].2H2O(1) (H2ihnpy=2-hydroxy-1-naphthaldehyde isonicotinoylhydrazone), K[MoO(O2)2 (Hihnpy)](2), K(Mo2O2(O2)4 (Hihnpy) (H2O)2](3), the oxo complexes [MoO2 (ihnpyH)-(HSO4)](4) and [MoO2 (ihnpy)].2H2O(5) have been prepared and characterized by elemental analyses, molar conductance, IR and IH NMR spectroscopic studies. On the basis of the spectroscopic evidence, H2 ihnpy coordinates to the molybdenum centre in the enol form in a bridging fashion in complexes (1) and (5) through the phenolic oxygen, enolic oxygen, azomethine nitrogen and pyridyl nitrogen atoms. In the complexes (2) and (3), H2 ihnpy coordinates to the molybdenum centre in the keto form as a monobasic bidentate ligand through the phenolic oxygen and azomethine nitrogen atoms. Peroxide is coordinated to the metal centre in a bidentate chelating fashion in the complexes (1), (2) and (3). The molecular oxoperoxo complex (1) on reaction with SO2 yielded the complex [MoO2. (ihnpyH) (HSO4)] (4) in which t...

Transition metal compounds of 1,2-bis(2-pyridyl)ethyne. Synthesis, spectroscopic characterization and X-ray structures of dinuclear [Cu 2(1,2-bis(2-pyridyl)ethyne) 3(NO 3) 4] and polynuclear [Co(1,2-bis(2-pyridyl)ethyne)(NO 3) 2] n

Five new compounds of the ligand 1,2-bis(2-pyridyl)ethyne ( 1), viz. [M(1,2-bis(2-pyridyl)ethyne)(NO 3) 2)] n (M = Co, Ni, Cu), [Zn(1,2-bis(2-pyridyl)ethyne)Cl 2] n and [Cu 2(1,2-bis(2-pyridyl)ethyne) 3(NO 3) 4] are described. The first four compounds, prepared from the ligand and the metal salts in ethanol, acetone or tetrahydrofuran (thf) are infinite chain compounds in the solid state, with the ligand serving to bridge the metal centers solely through the pyridine nitrogen atoms. A crystal structure of [Co(1,2-bis(2-pyridyl)-ethyne)(NO 3) 2)] n , space group Pbc2 1 shows that the coordination polymers are linear and parallel to the b-axis. The donor nitrogen atoms are coordinated to the cobalt ion in a cis arrangement with CoN distances of 2.073(6) and 2.076(6) Å. Each cobalt is further coordinated by two nitrate ions in an asymmetric chelating fashion with short cobalt to oxygen distances of 2.020(10) and 2.011(9) Å and two longer contacts at 2.473(13) and 2.458(12) Å. Reaction of ligand 1 with Cu(NO 3) 2 in ethanol gave a complex in which, in the solid state, two molecules of the ligand act in a monodentate manner toward copper, and a single ligand acts as a didentate ligand. The compound [Cu 2(bis(2-pyridyl)acetylene) 3(NO 3) 4] crystallizes in the P-1 space group. The Cu(II) ions within the dinuclear molecule are at a distance of 6.909(8) Å, while the Cu(II)Cu(II) distance in neighboring molecules is 6.845(8) Å. Each copper ion is coordinated by two pyridyl nitrogens, each at a distance of 1.995(3) Å, in a trans fashion, by two nitrate ions in an asymmetric chelating fashion with the short Cu(II) to oxygen distances of 2.001(3) and 2.002(3) Å, and by two additional nitrate oxygens at 2.560(4) and 2.448(4) Å, completing a distorted octahedron. Substantial differences in the IR spectra of the nitrate complexes between samples prepared in KBr and fluorinated mineral oil (KelF) can be explained in terms of displacement of part of the nitrate ions by bromide under moderate pressure, a phenomenon observed earlier by some of us in complexes of substituted pyrazoles.

Basal site substitution in the sulfido-bridged cluster Ru3(CO)9(μ3-S)2 by the redox-active diphosphine 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd). Synthesis, X-ray structure and electrochemical properties of Ru3(CO)7(bpcd)(μ3-S)2

Abstract The sulfido-bridged cluster Ru 3 (CO) 9 ( μ 3 -S) 2 ( 1 ) has been allowed to react with the redox-active diphosphine ligand 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) in the presence of Me 3 NO to give the new cluster Ru 3 (CO) 7 (bpcd)( μ 3 -S) 2 ( 2 ) in 61% yield. The ancillary bpcd in 2 is bound at one of the basal ruthenium sites in a chelating fashion, being derived by the replacement of axial and equatorial CO groups. This cluster represents the first example of a cluster derived from Ru 3 (CO) 9 ( μ 3 -S) 2 that contains a chelating diphosphine ligand. Cluster 2 has been characterized in solution by IR and NMR ( 1 H and 31 P) spectroscopies and in the solid state by X-ray diffraction analysis. Ru 3 (CO) 7 (bpcd)( μ 3 -S) 2 , which exists as two crystallographically independent molecules in the unit cell, crystallizes in the monoclinic space group P2 1 /c, a= 19.451(1), b = 21.865(2) A , Z = 8, D calc = 1.702 cm −3 ; R = 0.0411 , R w = 0.0447 for 5622 observed reflections. The redox properties of 2 were explored by cyclic voltammetry in MeCN, which revealed the presence of a reversible one-electron reduction process (bpcd based) and an irreversible oxidation (metal based). The natture of the HOMO and LUMO in 2 has been examined by carrying out extended Huckel MO calculations on the model cluster Ru 3 (CO) 7 (H 4 -bpcd)( μ 3 -S) 2 , and the results are discussed relative to the observed electrochemistry.

Ligand substitution of the redox-active diphosphine 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) in the alkynyl-bridged cluster Ru 3(CO) 9( μ2-H)( μ3- ν2-CC tBu). Synthesis, X-ray structure and electrochemical properties of Ru 3(CO) 7( μ2-H)( μ3- ν2-CC tBu) (bpcd)

The alkynyl-bridged triruthenium cluster Ru 3(CO) 99 μ 2-H( μ 3- ν 2-C tBu) ( 1) reacts with the redox-active diphosphine ligand 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3,-dione (bpcd) in the presence of Me 3NO to afford the new cluster Ru 3(CO) 7( μ 2-H)( μ 3- ν 2-CC tBu)(bpcd) ( 2) in 76% yield. The diphosphine ligand in 2 is bound at the unique ruthenium atom in a chelating fashion, and is the first example of a cluster-coordinated bpcd ligand. Cluster 2 has been characterized in solution by IR and NMR ( 1H and 31P) spectroscopy and in the solid state by X-ray diffraction analysis. Ru 3(CO) 7( μ 3- ν 2-CC tBu)(bpcd), as the CH 2Cl 2 solvate, crystallizes in the monoclinic space group P2 1/c: α = 21.190(1), b = 12.345(1) A ̊ , c = 17.272(1) A ̊ , β = 95.075(5)°, V = 4500.5(5) A ̊ , 3, Z = 4, d calc = 1.667 g cm −3; R = 0.399, R w = 0.0432 for 3255 observed reflections. The redox properties of 2 were explored by cyclic voltammetry, which revealed the presence of a reversible one-electron reduction process (bpcd based) and an irreversible oxidation (metal based). The nature of the HOMO and LUMO in 2 has been examined by carrying out extended Hückel MO calculations on the model cluster Ru 3(CO) 7( μ 2-H)( μ 3- ν 2-CCHH 4-bpcd), and the results are discussed with respect to the observed electrochemistry. The propensity of cluster 2 to undergo P-C bond cleavage is discussed in the light of other diphosphine ligand work.

Phosphanimin-Komplexe von Mangan(II)halogeniden. Die Kristallstrukturen von [MnCl2(Me3SiNPEt3)]2, [Mnl2(Me3SiNPEt3)2] und [MnI2(Me2Si(NPEt3)2)] / Phosphaneimine Complexes of Manganese(II)halides. The Crystal Structures of [MnCl2(Me3SiNPEt3)]2, [Mnl2(Me3SiNPEt3)2] and [MnI2(Me2Si(NPEt3)2)

The phosphaneimine complexes [MnCl2(Me3SiNPEt3)]2 (1) and [MnI2(Me3SiNPEt3)2] (2) have been prepared by the reaction of Me3SiNPEt3 with MnCl2 and Mnl2, respectively. Thermal decomposition of 2 leads to the chelate complex [MnI2(Me2Si(NPEt3)2)] (3) by cleaving SiMe4. The complexes are characterized by IR spectroscopy and by crystal structure determinations. 1: Space group P21/c, Z = 4, structure solution with 5062 observed unique reflections, R = 0.047. Lattice dimensions at -55 °C: a = 1175.8(5), b = 1634.5(2), c = 1740.2(8), β = 99.58(2)°. 1 forms dimeric molecules via chloro bridges and a cis-arrangement of the Me3SiNPEt3 donor molecules with Mn-N bond lengths of 210.4(5) and 208.2(4) pm. 2: Space group P 41212, Z = 4, structure refinement with 1633 independent reflections, 1072 observed unique reflections, R = 0.053. Lattice dimensions at -60 °C: a = b = 949.5(1), c = 3345.2(7) pm. 2 forms monomeric molecules with tetrahedrally coordinated Mn atoms and Mn-N bond lengths of 220.7(13) pm. 3: Space group P21/c, Z = 4, structure refinement with 8419 independent reflections, 4584 observed unique reflections, R = 0.047. Lattice dimensions at 20 °C: a = 1343.3(1), b = 2508.2(2), c = 1535.1(1) pm, β = 91.742(5)°. 3 forms monomeric molecules with the [Me2Si(NPEt3)2] ligand bound in a chelating fashion with Mn-N bond lengths of 212.9 pm in average.

The preparation and crystal structures of Cu(Hdpa)(chp) 2 and a new phase of Cu(dpa) 2 [Hdpa = 2-(pyridyl-2-amino)-pyridine, Hchp = 6-chloro-2-hydroxypyridine

The synthesis and crystal structure of Cu(Hdpa)(chp) 2 ( I) are reported. The copper environment is six coordinate with Hdpa and one of the chp ligands bonding in a chelating fashion. The second pyridine is bound through N, the O atom takes up the sixth coordination site but is also hydrogen bonded to the Hdpa ligand of a second Cu(Hdpa)(chp) 2 unit, forming a centrosymmetric dimer. A new (orthorhombic) phase of Cu(dpa) 2 ( II) has also been found, in which distorted tetrahedral copper(II) complexes are linked through a network of H bonds between the deprotonated dpa ligand and CH bonds meta- to the pyridyl nitrogen donor.

The chemistry and applications of organotin(IV) complexes of phosphorus-based acids

Synthesis, reactivity, structural aspects and applications of organotin(IV) complexes with phosphorus-based acids are reviewed. Complexes are classified according to the number of organic groups on tin and the nature of the donor atoms (oxygen and/or sulphur) on phosphorus. In general, organotin complexes of these acids are synthesized either by the reaction of organotin oxide with a free ligand or by treating the organotin halide with the alkali metal salt of an add. Reactions of monoorganotin oxides with phosphorus-based adds proceed in a stepwise manner involving a variety of organotin clusters, some of which are now fully characterized. The structure of the organotin complexes of these ligands is influenced by the number of R groups on tin and the donor set of phosphorus (>PO 2, >POS, >PS 2). The >PO 2-type ligands usually prefer bidentate bridging or a chelating bonding mode, while >PS 2-type ligands bind an organotin moiety in a monodentate or chelating (asymmetric or symmetric) fashion. The application of these complexes as catalysts, corrosion inhibitors and biocides is discussed.

1-Methyl-2-Chlor-3-Dichlorphosphinyl- und 1-Methyl-2-Methoxy-3-Dimethoxyphosphinyl-1,3,2λ3-Diazaphosphorinan Als Liganden in ÜBergangsmetallkomplexen; Synthese und Struktur von Tetracarbonyl-MolybdäN(0)-Koordinationsverbindungen und Eines Ionischen Bis-Chelat-Platin(II)-Chlorid-Komplexes

Abstract The reaction of 1-methyl-2-chloro-3-dichlorophosphinyl-1,3,2λ3-diazaphosphorinane 1 with (norbornadiene)tetracarbonylmolybdenum(0) in a 2:1 molar ratio furnished cis-bis(1-methyl-2-chloro-3-dichlo-rophosphinyl-1,3,2-diazaphosphorinane)tetracarbonylmolybdenum(0) 2. In 2, one ligand 1 is bonded to Mo(0) via the Pcl group, the other through the Pl2 group. 1-Methyl-2-methoxy-3-dimethoxyphos-phinyl-1,3,2λ3-diazaphosphorinane 3 reacted with norbornadienetetracarbonyl-molybdenum(0) to form the chelate complex cis-(1-methyl-2-methoxy-3-dimethoxyphosphinyl-1,3,2-diazaphosphorinane)tetracarbonylmolybdenum(0) 4, in which one molecule of the ligand 3 is attached to Mo(0) in a chelating fashion, coordinating through both the POCH3 and the P(OCH3)2 group. In the reaction of 3 with (COD)PtCl2 (COD = 1,5-cyclooctadiene) in a 2:1 molar ratio the ionic bis-chelate complex cis-bis(1-methyl-2-methoxy-3-dimethoxyphosphinyl-1,3,2-diazaphosphorinane)-platinum(II)chloride 5 was formed. Two molecules of 3 are coordinated...

Studies on organolanthanide complexes. Part 55. Synthesis of furan-bridged bis(cyclopentadienyl) lanthanide and yttrium chlorides, and ligand and metal tuning of reactivity of organolanthanide hydrides (in situ)

Four new complexes [{Ln[[graphic omitted]CH(CH2C5H4)]Cl}2](Ln = Y, Yb, Sm or Nd) were synthesised by using furan-bridged bis(cyclopentadienes) as ancillary ligands and characterized by elemental analyses, mass, IR and 1H NMR spectroscopy. The spectra indicate that these complexes are chloride-bridged dimers and the two furan-bridged cyclopentadienyl rings co-ordinate to each metal in a chelating fashion with in transolecular co-ordination between the oxygen atom and the metal. The effects of the bridging chain and the central metal upon the reactivity of organolanthanide hydrides generated in situfrom the [Ln(C5H5)2Cl]–NaH system were investigated. The reactivity can be tuned not only by varying the ligands but also by taking advantage of the lanthanide contraction. The ligand tunability varies for different reactions. More reactive organolanthanide hydride species (in situ) can be obtained by both ‘ligand tuning’ and ‘metal tuning’, i.e. by selecting the appropriate ancillary ligands and the early lanthanide metals.

Reactivity of the cyclic tetranuclear complex [Pd 4(μ- o-C 6H 4) 2(μ-O 2CMe) 4(μ-SPr i2) 2

Bridge splitting reactions of the cyclic tetranuclear complex, [Pd 4(μ-o-C 6H 4) 2(μ-O 2CMe) 4(μ-SPr i 2) 2], with neutral and anionic ligands afforded a variety of dinuclear palladium(II) complexes. In addition to the common one bridging o-phenylene ligand, the products contained different bridging ligands depending upon the ligand used. Dpm (Ph 2PCH 2PPh 2) or btmp (PhCH 2SCH 2PPh 2) acted as bidentate bridging ligands to give [Pd 2(μ-o- C 6H 4)(O 2CMe) 2(μ-L 2) 2] (L 2 = dpm, btmp). In contrast, Me 2bpy (4,4′-dimethyl-2,2′-bipyridyl) behaved as a bidentate chelating ligand to afford a cationic complex bearing the μ-acetato ligand, [Pd 2(μ- o-C 6H 4)(μ- O 2CMe)(Me 2bpy) 2](MeCO 2). In the case of Tl(acac), the acac ligand coordinated in a bidentate chelating fashion to yield a μ-sulfide complex, [Pd 2(μ- o-C 6H 4))(acac- O, O′) 2 (μ-SPr i 2)]. This complex further reacted with 3,5-lutidine to give [Pd 2(μ- o-C 6H 4))(acac- O, O′) 2(3,5-lut) 2 ]. Complexes obtained here were characterized by means of elemental analyses, NMR and IR spectroscopies.

Carbene complexes: XXII. Preparation, properties and structures of the N,N-functionalized bis(amino)carbenemolybdenum(O) carbonyls [ [formula omitted] { [formula omitted]CH 2)}] and [formula omitted]Ph 2] (CH 2) 2N {(CH 2) 3PPh 2}] n

Treatment of 1,2-bis(γ-diphenylphosphinopropylamino)ethane [obtained from 1,2-bis(allylamino)ethane and 2PPh 2H and CH(NMe 2)(OMe) 2] yielded the electron-rich enetetramine ▪CN(R)(CH 2) 2NR] 2 [R  CH 2) 3PPh 2] [abbreviated as L 2 (CH 2) 3PPh 2 ]. Although L 2 All, the analogue in which R  CH 2CH:CH 2, is unknown, the carbenemolybdenum title compounds [Mo(CO) 4(L All] ( 3) and ▪ Mo(CO) 3 {L (CH 2) 3 PPh 2 ] n ( 4) have been prepared from [Mo(CO) 6]: for 3 from CH(NMe 2)(OMe) 2 + [All(H)N(CH 2)] 2 and for 4 from L 2 (CH 2) 3PPh 2 . In 3 only one of the R groups behaves in a ligating mode. L All being a chelating ligand, 3 is thus a rare example of a metal complex having both carbene- and η 2 -alkene-ligation and the first for molybdenum. The presumed polymeric structure of 4 is believed to arise from one of the P III sites behaving in a chelating fashion with the other in a bridging mode. Treatment of 3 with 13CO stereoselectively gave the isotopomer in which a CO trans to a CO was displaced, the trans effect thus being parallel to the trans influence (X-ray data); a coproduct was cis-[Mo(CO) 4( 13CO)(L All)]. Similarly, cis-[Mo(CO) 4(L All)(PEt 3)] was the sole product of reaction between 3 and PEt 3, which upon irradiation yielded fac- together with mer-[Mo CO) 3(L All)(PEt 3)]. Thermolysis of 3 afforded AllC: N(CH 2) 2NAll as the only organic product. The X-ray structure of 3 showed that the mutually trans Mo CO bonds are significantly longer [av. 2.037(5) Å] than MoCO trans to carbene [1.984(4) Å] or alkene [1.975(5) Å], with Mo C carb at 2.229(4) Å.

Studies on organolanthanide complexes: XLVI. Synthesis and characterization of N-containing ring-linked biscyclopentadienyl lanthanide and yttrium chlorides

Four new title complexes, [CH 3N(CH 2CH 2C 5H 4) 2LnCl] 2 (Ln = Y, Yb, Sm, Nd), were synthesized by using amine-linked biscyclopentadiene, CH 3N(CH 2CH 2C 5H 5) 2, as ancillary ligands and fully characterized by elemental analyses, MS, IR and 1H NMR. Their spectroscopies indicate that these complexes are chloride-bridged dimers and the two amine-linked cyclopentadienyl rings coordinate to one metal in a chelating fashion with intramolecular coordination from the nitrogen atom to the metal.