Riad Fawzi

Synthesis of chiral and C2-symmetric iron(II) and cobalt(II) complexes bearing a new tetradentate amine ligand system

Abstract A synthesis for the new tetrapodal ligands [ N , N ′-dimethyl- N , N ′-di(quinoline-2-methyl)]-1,2-ethylene diamine (LO 1 ( 3a ) and [ N , N ′-dibenzyl- N , N ′-di(quinoline-2-methyl)]-1,2-ethylene diamine (L 2 ) ( 3b ) and for the related octahedral complexes (L 1,2 )FeCl 2 ( 6a and 6b ) and (L 1,2 )CoCl 2 ( 7a and 7b ) is given. The solid state structures of 3b and 6a have been determined. Three different modes are possible for a tetradentate coordination of L 1,2 to FeCl 2 or CoCl 2 . In 6a the ligand adopts a single chiral geometry around the ClFeCl plane.

Preparation, properties and reactions of metal-containing heterocycles ☆: Part C: tetraazatetraphosphadimolybdacyclophanes: synthesis, isolation, characterization, and X-ray crystal structures

The ditopic aminodiphosphines CH 2 (4,4′-Ph 2 PNHC 6 H 4 ) 2 ( 2 ) and CH 2 (4,4′-Ph 2 PCH 2 NHC 6 H 4 ) 2 ( 5 ) are obtained by reaction of 4,4′-diaminodiphenylmethane with ClPPh 2 and (i) (CH 2 O) n /NaOMe/(ii) HPPh 2 , respectively. Treatment of (η 4 -nbd)Mo(CO) 4 with 2 and 5 under high-dilution conditions in CH 2 Cl 2 affords the tetraazatetraphosphadimolybdaclophanes [CH 2 (4,4′-(OC) 4 Mo(Ph 2 PNHC 6 H 4 ) 2 )] 2 ( 3 ) and [CH 2 (4,4′-(OC) 4 Mo(Ph 2 PCH 2 NHC 6 H 4 ) 2 )] 2 ( 6 ) in relatively high yields. The structures of 3 and 6 were investigated by X-ray crystal-structure analyses. Whereas the cavity of the molecular structure of 3 can be described by a parallelogram, that of 6 has the shape of a boat in which the diphenylmethane building blocks form the hull and the cis -(Ph 2 P) 2 Mo(CO) 4 fragments represent the bow and stem, respectively. Because of the formation of only very weak hydrogen bonds in 3 and 6 , no binding to molecules like p -benzoquinone, 1,4-cyclohexanedione, 2,5-piperazinedione and trans -1,4-diaminocyclohexane could be detected.

Chemical properties and cytotoxic activity of complexes of platinum(II) and palladium(II) containing dmso and various anions; synthesis and structural characterization of [Pt(dmso)2{O2(CO)2CCH2CH2CH2}]

Treatment of cis-[Pt(dmso)2Cl2] with 2 mol of KBr or KI leads to the formation of the analogous dibromide or diiodide complexes. Treatment of [M(dmso)2Cl2] [M = Pt (cis-) or Pd (trans-)] with AgNO3 (2 mol) in H2O followed by 1mol of potassium oxalate, maleate, cyclobutane dicarboxylate (CBDC), malonate or 2mol of potassium cyclohexane carboxylate or pivalate leads to the formation of the corresponding PtII and PdII carboxylate complexes. The single crystal X-ray structure determination of [Pt(dmso)2(CBDC)] has been discussed and compared with data on other related complexes. The in vitro cytotoxic activity of some of these complexes against eight tumour cell lines has been examined using the MTT-colorimetric assay.

Substrate activation by the Wilkinson analogous complex containing η2-chelated and η1 P-bonded (methoxyethyl)dicyclohexylphosphine as a hemilabile ligand

Abstract In the presence of a variety of small molecules the pseudo 14-electron rhodium complex -chelated Cy 2 PCH 2 CH 2 OCH 3 ligand; P ∼ O = η 1 ( P )-coordinated) is shown to undergo a facile cleavage of its intramolecular ether moiety. The reaction of 1 with ethene, diphenylacetylene and carbon disulfide results in the irreversible coordination of the corresponding molecule to the metal yielding the complexes ClRh(C 2 H 4 )(P ∼ O) 2 ( 2 ), ClRh(PhC≡CPh)(P ∼ O) 2 ( 3 ), ClRhCS 2 (P ∼ O) 2 ( 4 ), and ClRhCS(P ∼ O) 2 ( 5 ). All compounds are obtained in excnt yields under very mild conditions. The structures of 4 and 5 were determined by single-crystal X-ray diffraction. The oxidative addition of HCl to the starting material 1 leads to the monochelated octahedrally coordinated complex ( 6 ). Complex 6 exhibits fluxional behavior on the 31 P NMR time scale. Line-shape analysis of variable temperature 31 P{ 1 H} NMR spectra of 6 affords the Eyring parameters ΔH ± = 42.3kJ mol −1 and ΔS ± = −63.7 J mol −1 K −1 , indicating an intramolecular exchange mechanism. The RhH bond in 6 is able to insert ethene to give the ethylrhodium(III) complex Cl 2 RhC 2 H 5 ( P ∼ O ) 2 ( 7 ) . Subsequently, there follows a fast σ π rearrangement to the complex Cl 2 Rh( η 2 -C 2 H 4 )(H)(P ∼ O) 2 ( 8 ) which undergoes a slow π σ transformation to the monochelated product ( 9 ).

cis,cis-1,3,5-Tris(diphenylphosphino)cyclohexane (tdppcy). A new tripodal phosphine that forms metal complexes with adamantane-type structures. rystal structure of Ir(tdppcy)Cl3

Abstract The novel tridentate phosphine cis , cis -1,3,5-tris(diphenylphosphino)cyclohexane (tdppcy) ( 3 ) has been synthesized. Treatment of tdppcy with Mo(C 7 H 8 )(CO) 3 and Ir(PPh 3 ) 2 (CO)Cl yields octahedral Mo(tdppcy)(CO) 3 ( 4 ) and trigonal-bipyramidal Ir(tdppcy)(CO)Cl ( 5 ), respectively. Compound 5 is transformed into either Ir(tdppcy)(CO)H ( 6 ) or Ir(tdppcy)(CO)(H) 2 + ( 7 ) by treatment with NaBH 4 in refluxing THF. Complex 5 can be oxidized by dichloromethane or Cl 2 to the trichloro complex Ir(tdppcy)Cl 3 ( 8 ), which can be converted into the dihydride Ir(tdppcy)(H) 2 Cl ( 9 ) by treatment with NaBH 4 in THF. The dynamic behavior of the highly fluxional pentacoordinate complexes 5 and 6 has been studied by VT 31 P{ 1 H} NMR spectroscopy. An X-ray diffraction study has been carried out on 8 ·3CH 2 Cl 2 .

PALLADIUM(II) COMPLEXES WITH HEMILABILE ETHERDIPHOS LIGANDS IN THE ALTERNATING COPOLYMERIZATION OF CARBON MONOXIDE WITH OLEFINS

Abstract The potentially hexadentate diphos ligands (ROCH 2 CH 2 ) 2 P(CH 2 ) 3 P(CH 2 CH 2 OR) 2 ( 1a-d ) (R=Et ( a ), n -Bu ( b ), t -Bu ( c ), Cy ( d )) are accessible by photochemically induced hydrophosphination of the vinyl ethers CH 2 CHOR with the diprimary phosphine H 2 P(CH 2 ) 3 PH 2 . Treatment of 1a–d with (PhCN) 2 PdCl 2 in CH 2 Cl 2 leads to the dichlorodiphospalladium(II) complexes 2a–d , from which the dicationic palladium(II) complexes 3a–d were obtained by abstraction of the chlorides with AgBF 4 in CH 2 Cl 2 . In 3a–d the etherdiphos ligands are coordinated in a η 4 (O,P;O′,P′) fashion. A rapid chemical exchange between the η 2 -P ∩ O chelated and the η 1 -P coordinated part of the ligands in 3a–d was demonstrated by means of temperature-dependent 13 C{ 1 H} NMR spectroscopy. Both PdO bonds in 3a–d are easily cleaved by polar solvents such as acetonitrile and water resulting in the formation of the adducts 3b  · 2CH 3 CN, 3c  · H 2 O, and 3c  · 2H 2 O. The molecular structures of 2a and 3c  · H 2 O were determined by single crystal X-ray diffraction methods. Under a total pressure of 60 bar ethene/CO and propene/CO, respectively, 3a-d are highly active catalysts in the copolymerization of olefins with carbon monoxide. GPC measurements revealed high molecular weights of these polyketones.

ZUR OXIDATION VON 2-SELENOIMIDAZOLINEN MIT IOD1

Abstract The stepwise oxidation of 2-selenoimidazolines 1 (ImSe; Im = 1,3-dihydro-1,3,4,5-tetraalkyl-2H-imi-dazol-2-ylidene) leads to a series of carbene stabilised selenium iodine compounds whose composition depend from the stoichiometry and the substituents at the nitrogen atoms. No diselenides or selenium(IV) compounds have been detected. The X-ray structures of the compounds [ImSeSelm]2+ (3c), (ImSel2)2I2 (5c) and (ImSel)I3 (6b) are reported.

Synthese und reaktivität kohlenwasserstoffüberbrückter komplexe von Mangan, Rhenium, Molybdän und Wolfram

Abstract The hydrocarbon-bridged complexes M(CH 2 ) n M (M = Mn(CO) 5 : n = 5 ( 2b ), 10 ( 2c ); M = Re(CO) 5 : n = 5 ( 3b ), 10 ( 3c ); M = (η 5 -C 5 H 5 )Mo(CO) 3 : n = 5 ( 4b ), 10 ( 4c ); M = (η 5 -C 5 H 5 )W(CO) 3 : n = 10 ( 5c )) are obtained by reaction of the bistriflates Y(CH 2 ) n Y (Y = F 3 CSO 3 , n = 5 ( 1b ), 10 ( 1c )) with the carbonyl metalates [M(CO) 5 ] − (M = Mn ( 2 ), Re ( 3 )) and [(η 5 -C 5 H 5 )M(CO) 3 ] − (M = Mo ( 4 ), W ( 5 )) in diethyl ether and THF, respectively. Depending on the solvent, the reaction of 1b with 2 also affords the cyclic carbene complex 2d . The action of SO 2 and CO, respectively, on the complexes 2a - c and 4b , c results in the formation of the sulfinato-S complexes [(η 5 -C 5 H 5 )(OC) 3 MoSO 2 (CH 2 ) n O 2 SMo(CO) 3 (η 5 -C 5 H 5 )] ( n = 5 ( 4b ′), 10 ( 4c ′)) and the diacyl-bridged compounds [(OC) 5 MnC (O)(CH 2 ) n (O)CMn(CO) 5 ] ( n = 3 ( 2a ′), 10 ( 2c ′)). According to an X-ray structural analysis, the monoacyl complex [(OC) 5 MnC(O)(CH 2 ) 3 Mn(CO) 5 ] ( 2e ) crystallizes in the orthorhombic space group Cmca with Z = 4, the acyl function being disordered. 1 H NMR spectroscopic investigations indicate a hindered rotation about the C α C β -σ bond in 2b,c and 3b,c .

HETEROCYCLEN ALS LIGANDEN XXII. 2-CHALKOGENOIMIDAZOLINE ALS LIGANDEN IN PENTACARBONYLMETALL-KOMPLEXEN

Abstract The chalcogenoimidazoline complexes N—CMe—CMe—NR—C=X·M(CO)3 (VIII-XI; R = Me, iso-Pr; X = S, Se, Te; M = Cr, Mo, W) are obtained from the metal hexacarbonyls (M = Cr, Mo, W) and the chalcogenoimidazolines IV-VII. In these complexes the chalcogeno ligands exhibit strong donor properties according to the sequence Te > Se > S which is demonstrated by n. m. r. and i. r. data. The X-ray structures of N(iso-Pr)—CMe—CMe—N(iso-Pr)—C=X·Cr(CO)3 (X = S; Se; VIIIa, IXa) are reported.

Darstellung und eigenschaften von und reaktionen mit metallhaltigen heterocyclen: XLVI. Synthese, struktur und chemisches verhalten siebengliedriger mangana- und rhenacycloalkane☆

Abstract The substitution compounds Br(OC) 4 MPPh 2 (CH 2 ) n Cl (M = Mn, Re; n = 5, 6) are obtained by the action of the (5-chloropentyl- and 6-chlorohexyl)diphenylphosphanes Cl(CH 2 ) n PPh 2 , which are formed from the α,ω-dihalogenoalkanes Cl(CH 2 ) n Cl and NaPPh 2 on the manganese and rhenium complexes BrM(CO) 5 in cyclohexane. If they are subjected to reductive cycloelimination with sodium amalgam in THF only the seven-membered mangana- and rhenacycloheptanes (OC) 4 MPPh 2 (C H 2 ) 5 can be isolated in satisfactory yields. They crystallize in the triclinic space group P 1 with Z = 2 . The influence of the ring size of the heterocycles (OC) 4 MPPh 2 (C H 2 ) n (M = Mn, Re; n = 1–5) on the bonding parameters and on the reactivity of the MC σ bond is investigated. Insertion of CO into the MnC bond and of SO 2 into the ReC σ bond of (OC) 4 MPPh 2 (C H 2 ) 5 affords the cyclic acyl and sulfinato complexes (OC) 4 MnPPh 2 (CH 2 ) 5 C O and (OC) 4 RePPh 2 CH 2 ) 5 S O 2 , respectively.