Jean Dehand

Structure cristalline et moleculaire du tetracarbonylcobaltatopyridine (N-(phenylamino)-α-methylbenzylidenimino-2-C,N) palladate(II), compose a liaison PdCo

Abstract The crystal and molecular structure of a bimetallic complex containing a PdCo bond has been determined by a single-crystal X-ray study. The compound crystallizes in the monoclinic space-group P21/n, with Z = 4. The intensities were measured on a Nonius CAD-4 automatic diffractometer. The structure has been refined to R and R″ values of 0.068 and 0.058 for 2843 independent reflections. The molecule contains a cyclopalladated ring system, with PdC and PdN(1) bond lengths of 1.998(8) and 2.101(5) A, respectively. Furthermore, the palladium atom is bonded to a pyridine ring (PdN(3) 2.159(6) A) and to a Co(CO)4 group, trans to N(1), through a PdCo bond of length 2.604(1) A.

Reactivity of cyclopalladated complexes. Part 5. Insertion reactions of diphenylacetylene, 1-phenylprop-1-yne, and hexafluorobut-2-yne with cyclopalladated compounds. Crystal and molecular structure of chloro{3–4-η-4-[(2-dimethylaminomethyl)phenyl]-1,4-dimethyl-2,3-diphenylbuta-1,3-dienyl-C1N}palladium(II) and bromo{3–4-η-4-[(2-dimethylaminomethyl)phenyl]-2,4-dimethyl-1,3-diphenylbuta-1,3-dienyl-C1N}-palladium(II)

Reactions between disubstituted alkynes RC2R′(R = R′= Ph and R = Me, R′= Ph) and [{Pd(dmba)X}2](dmba =NN-dimethylbenzylamine, X = Cl or Br) afford bis-insertion products [Pd{(RCCR′)2C6H4CH2NMe2}X] in high yield. With MeC2Ph two isomers have been isolated, (1bα) and (1bβ). In order to establish their molecular structures, a single-crystal X-ray diffraction study has been made on the chloro-derivative of (1bβ) and the bromo-derivative of (1bα). Crystals of (1bα; X = Br) are monoclinic, space group P21/c, Z= 4, with a= 15.362(13), b= 12.368(5), c= 14.886(11)A, and β= 94.86(13)°. The structure has been refined to R 0.078 (R′ 0.105) for 2 529 independent reflections; the two acetylenes inserted into the Pd–C bond have a head-to-tail arrangement, the Pd being σ-bonded to a carbon bearing a phenyl group. Crystals of (1bβ; X = Cl) are monoclinic, space group P21, Z= 2, with a= 8.227(6), b= 16.059(33), c= 8.923(9)A, and β= 99.30(12)°. The structure has been refined to R 0.074 (R′ 0.065) for 2 077 independent reflections. The molecule shows a tail-to-tail arrangement for the two inserted acetylenes, the carbon σ-bonded to the palladium bearing a methyl group. The corresponding reaction with the 8-methylquinoline palladated dimer affords a benzenoid trimer via a bis-insertion analogue which was isolated for R = R′= Ph. Hexafluorobut-2-yne (hfb) reacts with the above palladated dimers and those formed from benzo[h]quinoline and NN-dimethyl-1-naphthylamine to give novel halide-bridged binuclear complexes with seven-membered rings. They are formed by formal insertion of one hfb unit into the Pd–C σ bond. With the naphthylamine dimer only an organic compound was isolated. The novel dimeric complexes easily afford monomeric derivatives by bridge-splitting reactions with pyridine or PPh3.

Influence of electronic factors on metal—metal stretching frequencies in linear trimetallic systems

IR stretching frequencies are reported for new linear metal—metal bonds in the complexes [M″AuM″]− (M″ = Mn(CO)5, Co(CO)4, η-C5H5 Mo(CO)3, η-C5H5Fe(CO)2) and correlations are established between oxidation state, coordination number of M′ in linear M″M′M″ systems (M′ = PdII, PtII, HgII, AuI) and the corresponding v(M′M″) stretching frequencies.

Composes organometalliques a liaisons metalmetal : III. Systemes lineaires M2M1L2M2 OU M1 = PdII, PtII; M2 = Mn(CO)5; L = Py, 3-MePy, 4-MePy☆

Abstract The synthesis and vibrationl spectra of trans -M 1 L 2 [Mn(CO) 5 ] 2 compounds (M 1 = Pd II , Pt II ; L = Py, 3=MePy, 4-MePy) are presented. The linear bonding MnM 1 Mn, together with the strongly anionic character of the Mn(CO) 5 group, are supported by IR spectroscopy of the v 35 (M 1 Mn) and v (CO) vibrations.Abstract The synthesis and vibrationl spectra of trans-M1L2[Mn(CO)5]2 compounds (M1 = PdII, PtII; L = Py, 3=MePy, 4-MePy) are presented. The linear bonding MnM1Mn, together with the strongly anionic character of the Mn(CO)5 group, are supported by IR spectroscopy of the v35(M1Mn) and v(CO) vibrations.

Composes organometalliques a liaisons metal—metal : VII. Complexes bimetalliques du nickel avec des metaux de transition intermediaires dans la redistribution de coordinats PPh3, Co et NO

Abstract The reactivity of the nickel complexes Ni(PPh 3 ) 2 X 2 and NiNO(PPh 3 ) 2 X (X  Cl, Br, I) towards carbonylmetallate anions (M 2 ) − (M 2  Co(CO) 4 , Fe(CO) 3 NO, Mn(CO) 5 , η 5 -C 5 H 5 Fe(CO) 2 , η 5 -C 5 H 5 Mo(CO) 3 , ) has been studied. The nucleophilic substitution of X by M 2 leads initially to a metal—metal bonded intermediate which generally decomposes with ligands redistribution between the transition metals. This affords always as only Ni derivative Ni(CO) 2 (PPh 3 ) 2 and, with Ni(PPh 3 ) 2 X 2 a M 2 phosphine substituted complex, with NiNO(PPh 3 ) 2 X a M 2 nitrosyl complex. Only two metal—metal bonded complexes could be isolated: ON(PPh 3 ) 2 NiCo(CO) 4 and ON(PPh 3 ) 2 NiFe(CO) 3 NO which are the first bimetallic Ni to transition metal directly bonded complexes, without bridged ligand. We suggest that the migrations of ligands between the metals follow an intermolecular mechanism with PPh 3 and an intramolecular one with CO and NO.

trans-Bis(tetracarbonylcobaltato)bis(pyridine)platinum(II) and trans-bis(pentacarbonylmanganato)bis(pyridine)- platinum(II)

The preparation and properties of trans-PtPy2[Co(CO)4]2 and trans- PtPy2[Mn(CO)5]2 are described. The metal carbonyl anion Co(CO)−4 is studied as a leaving group by measuring the rate of the cleavage reaction PtPy2[Co(CO)4]2+2 Y ⇌ [PtPy2Y2]2+ + 2 Co(CO)−4 Y = (C6H5)3P, (n-C4H9)3P in tetrahydrofuran. The products of these reactions are also described.

Composes organometalliques a liaisons metal—metal : VI. Nouveaux composes bimetalliques a liaisons pdCo et PdMo☆☆☆

Abstract The reaction of a chelated palladium compound Pd(CN)LCl with Co(CO) 4 − and Mo(CO) 3 -η-C 5 H 5 − gives new bimetallic PdCo and PdMo complexes when L = pyridine. The metal—metal bond is trans with respect to the Pd—carbon σ-bond. With Mn(CO) 5 − and Fe(CO) 2 -η-C 5 H 5 − the complexes are too unstable to be isolated. No reaction is observed between Co(CO) 4 − or Mo(CO) 3 -η-C 5 H 5 and Pd (CN)-LCl when L = PEt 3 , PPh 3 , nor between Co(CO) 4 − and the anionic complex [Pd(CN)Cl 2 ] − . These results are ascribed to steric hindrance. The bimetallic complexes react with PPh 3 with cleavage of the metal—metal bonds, affording ionic complexes. One of them, [Pd(CN)PPh 3 Py] [Mo(CO) 3 -η-C 5 H 5 ], decomposes with loss of the CN and Py ligands to give a new tetrametallic [PPh 3 PdMo(CO) 3 -η-C 5 H 5 ] 2 cluster.

Interaction of cis-diaminotolueneplatinum(II) with nucleosides: evidence for guanosine O(6).N(7) chelation by platinum

The binding of the anti-tumour agent cis-[Pt(dat)Cl2)(dat = 3,4-diaminotoluene) to nucleosides is reported; adenosine and cytidine act as monodentate ligands, via N(7) or N(3), respectively, and guanosine behaves as a bidentate ligand, the Pt atom being firmly bound at N(7) and weakly via O(6).

Synthesis of organometallic solvento complexes

Abstract The isolation and characterization of solvento complexes obtained from cyclic complexes of palladium are reported; the solvents coordinated to palladium are acetone, diethyl ketone, ethanol and tetrahydrofuran, and an order of the strengths of the Pd←O bonds is proposed

Metal-catalysed ring opening. Reactions of 2-amino-thiazole and -thiazoline with palladium(II) and platinum(II)

[PtCl4]2– and [Pd2Cl6]2– ions condense in basic media with an amino-substituted thiazoline or thiazole to give complexes in which ring opening has been induced by C–S bond cleavage.