Fadila Balegroune

A new approach to A,B-difunctionalisation of cyclodextrins using bulky 1,3-bis[bis(aryl)chloromethyl]benzenes as capping reagents

1,3-Bis[bis(4-tert-butylphenyl)chloromethyl]benzene and 1,3-bis[bis(4-anisyl)chloromethyl]benzene were employed as regioselective capping reagents for the preparation of C-6A,C-6B-bridged, permethylated alpha- and beta-CD derivatives; isolated yields up to 55% of proximally capped, methylated CDs were obtained, thus opening the way to the straightforward preparation of a wide range of A,B-functionalised CDs. As revealed by a single crystal X-ray diffraction study, the benzene-1,3-bis[bis(4-tert-butylphenyl)methyl] spacer is perfectly suited for A,B-capping of beta-cyclodextrin.

Synthesis and molecular structure of new families of iridium(III)-Cp★ and rhodium(III)-Cp★ complexes derived from 1,2-dicyanoethene-1, 2-dithiolate 2,2′-biimidazole or 2,2′-bithiazole. Single crystal structures of [(η5-Me5C5)Ir(biimH2)Cl]Cl and [(η5-Me5C5)Rh(dcdt)]

Reaction of [(η5-Me5C5)MCl2]2 (M  Ir or Rh) with 1,2-dicyanoethene-1,2-dithiolate (dcdt2−), 2,2′-biimidazole (biimH2), or 2,2′-bithiazole (bith) affords various d6 complexes in high yield. Pentacoordinate compounds such as [(η5-Me5C5)M(dcdt)] (M  Ir or Rh) and hexacoordinate complexes of the type [(η5-Me5C5)M(biimH2)Cl]Cl, (M  Ir or Rh) or [(η5-Me5C5)Ir(bith)Cl]Cl have been synthesized and characterized. [(η5-Me5C5)Rh (dcdt)] crystallizes in the orthorhombic space group C2221 with unit cell parameters a = 11.972 (3), b = 15.072 (4), c = 16.456 (5) A. Refinement of 859 observed reflections led to the final values of R = 2.31 and Rw = 3.46%. [(η5-Me5C5)Ir(biimH2)Cl]Cl crystallizes in the orthorhombic space group P212121 with unit cell parameters a = 14.610 (4), b = 14.556 (6), c = 8654 (3) A. Refinement of 1630 observed reflections led to a value of R = 186 and Rw = 2.65%. The biimH2-iridium complex exhibits a characteristic three-legged “piano-stool” arrangement and the dcdt-rhodium complex a flattened basket shaped arrangement.

Bimetallic alkoxysilyl complexes with bis(diphenylphosphino)methane, 2-(diphenylphosphino)pyridine or (diphenylphosphino)acetophenone ligands: crystal structure of [Fe{μ-Si(OMe)2(OMe)}(CO)3(μ-dppm)Pt(CNR)][PF6] (R = 2,6-xylyl)

Abstract The heterobimetallic carbene complexes [Fe{μ-Si(OMe) 2 ( OMe)}(CO) 3 (μ-dppm)P t{ C(CH 2 ) 2 CH(R)O }] [PF 6 ](R  H ( 2a ), Me ( 2b )) and isonitrile complexes [Fe{μ-Si(OMe) 2 ( OMe)}(CO) 3 (μ-dppm)P t(CN R][PF 6 ] (R = 2,6-xylyl ( 3a ), or t -butyl ( 3b )) have been prepared by the reaction of [Fe{μ-Si(OMe) 2 ( OMe)}(CO) 3 (μ-dppm)P tCl] with 3-butyn-1-ol or (±)-4-pentyn-2-ol or RNC respectively, in the presence of TIPF 6 . The (trimethoxy) silyl ligand bridges the two metals, as a result of a SiO→Pt interaction. The structure of 3a was refined to R = 0.029 and R w = 0.041 on the basis of 5764 reflections having F 0 2 > 3σ( F 0 2 ). Upon reaction of cis -[ MCl{(PhO) 2 P(OC} 6 H 4 )}{P(OPh) 3 }](M  Pt ( 5a ), or Pd ( 5b ) with K[Fe{Si(OMe 3 })(CO) 3 (η 1 -dppm)](K 1a ) the ortho -metallated heterobimetallic complexes cis -[Fe{Si(OMe) 3 })(CO) 3 (μ-dppm) Pt{P(OPh) 2 (OC 6 H 4 )}] ( 6a ) and trans -[Fe{Si(OMe) 3 }(CO) 3 (μ-dppm) Pd{P(OPh) 2 (OC 6 H 4 )}] ( 6b ) were formed. The phosphinopyridine- and ketophosphine-bridged complexes [Fe{Si(OMe) 3 }(CO) 3 (μ-Ph 2 Ppy)Pd(8-mq)] ( 8 ) and [Fe{Si(OMe) 3 }(CO) 3 {μ-Ph 2 PCH 2 C( O)Ph}P) d(8-mq)] ( 10 ) are described. We also discuss the preparation, dynamic behaviour and spectroscopic properties of heterobimetallic allyl-type complexes ([Fe{Si(OMe) 3 }(CO) 3 (μ-dppm)Ni(μ 3 -C 3 H 5 )] ( 11 ), [Fe{Si(OSiMe 3 ) 3 } (CO) 3 (μ-dppm)Pd(η 3 -C 3 H 5 )] ( 12a ), [Fe{SiMe(OSiMe 3 ) 2 }(μ-dppm)Pd(η 3 -C 3 H 5 )] ( 12b ), [Fe{Si (OMe) 3 }(CO) 3 (μ-Ph 2 Ppy)Pd(η 3 -RC 3 H 4 )] (R  H ( 13a ) or Me ( 13b )) and [Fe{Si(OMe) 3 }(CO) 3 - (μ-dppm)Pt(η 3 -C 8 H 13 )] ( 14 )). Treatment of [NiCp(PPh 3 )Br] with [NEt 3 H] 1a yielded the heterobimetallic complex [Fe{Si(OMe) 3 } (CO) 3 (μ-dppm)NiCp] ( 15 ).

Complexes of functional phosphines. Part 11. β-Ketophosphine complexes of nickel, palladium, and platinum. Crystal structures of trans-[NiX2(HL)2][X = Cl or I, HL = Ph2PCH2C(O)Ph]

The synthesis and spectroscopic properties (1H and 31P n.m.r., i.r.) of complexes containing the β-ketophosphine Ph2PCH2C(O)Ph (HL) are described. In [NiX2(HL)2][X = Cl (1), Br, or I (3)], [PdCl2(HL)2](4), [PtCl2(HL)2](5), and [{PdCl(µ-Cl)(HL)}2](6), HL behaves as a P-bonded monodentate ligand whereas in the cationic complexes [Pd(HL)2][BF4]2 and [{Pd(µ-Cl)(HL)}2][CF3SO3]2 it acts as a P,O chelate. The crystal structures of (1) and (3) have been determined using single-crystal X-ray diffraction methods. Compounds (1) crystallises in space group P21/n, with a= 10.079(3), b= 11.510(3), c= 15.411(3)A, β= 93.42(2)°, and Z= 2. Compound (3) crystallises in space group P21/c, with a= 9.283(1), b= 10.261(1), c= 19.318(1)A, β= 96.20(1)°, and Z= 2. The structures have been refined to R 0.050 (R′ 0.060) for (1) and to R 0.032 (R′ 0.041) for (3). The geometries of these complexes are essentially identical although the ν(CO) frequencies of these complexes are significantly different [1 662 cm–1 for (1) and 1 620 cm–1 for (3)]; the nickel atom occupies a centre of symmetry and has thus a square-planar environment. Although the ketone group is bent towards the nickel atom, no significant Ni–O bonding interaction occurs, as deduced from the Ni–O distances [3.230(4)A in (1) and 3.231(1)A in (3)]. In refluxing toluene (1), (4), or (5) lead to the phosphine–phosphinite complexes cis-[[graphic omitted]Ph2}](M = Ni, Pd, or Pt). Treatment of (1), (4), or (5) with base gives the enolato-complexes cis-[[graphic omitted]Ph}2](M = Ni, Pd, or Pt). Reaction of (6) with NaH affords the binuclear complex [{P[graphic omitted]Ph]}2]. The latter reacts with PPh3 to give cis-[P[graphic omitted]Ph}(PPh3)], and with Ph2PCH2CH2PPh2–TlPF6 to give [P[graphic omitted]Ph}(Ph2PCH2CH2PPh2)]PF6. The P–O coupling products [N[graphic omitted]R}](R = Cl or Ph) are obtained by reaction of the complex [N[graphic omitted]Ph}2] with PCl3 and PPhCl2 respectively, and shown to have a five-co-ordinate structure. The square-planar P,P,P complex [N[graphic omitted]Ph}]PF6 results from reaction of [N[graphic omitted]Ph}] with TIPF6.

Synthesis and crystal structures of heterobimetallic Fe-Cd, Fe-Zn, and Fe-In complexes containing hemilabile phosphorus/oxygen and silicon/oxygen bridging ligands

The reactions of K[Fe{Si(OMe)3}(CO)3(P∼Y)][P∼Y=Ph2PCH2C(O)Ph, Ph2PCH2C(O)[(η-C5H4)FeCp] (Cp=η5-C5H5), Ph2P(CH2)2CN] with CdCl2·2.5H2O, ZnX2 (X=Cl, I) or InCl3 afforded Fe-Cd-Fe or Fe-M(μ-X)2M-Fe (M=Cd, Zn, In;X=Cl, I) and Fe-InCl2 complexes. Some of them contain an unusual and labile μ-η2-SiO alkoxysilyl bridge which may be associated with a bridging mode for the ketophosphine ligand (first such example structurally established), thus providing original results in bimetallic chemistry on the intramolecular coordination of oxygendonor functions ofchemically different hemilabile ligands firmly attached to a neighboring metal center. The structures of the trinuclear complex (3), of the chlorobenzene solvate of the tetranuclear complex (4a·C6H5Cl) and of [mer-(OC)3{(EtO)3Si} (4e) have been determined by X-ray diffraction. Crystals of 3 are orthorhombic, space groupPbcn, witha=19.010(4),b=11.766(5),c=26.998(7)Å, andZ=4. Crystals of4a·C6H5Cl are monoclinic, space groupC2/c witha=22.455(3),b=17.680(2),c=16.627(4)Å, β=90.80(4)°, andZ=4. Crystals of4e are monoclinic, space groupC2/c witha=25.392(5),b=18.554(6),c=16.28(1)Å, β=120.73(3)°, andZ=4. The structures were solved using direct methods and Fourier difference techniques and refined by blocked full-matrix least squares toR=0.035 (Rw=0.049) for 2719 observed reflections, toR=0.042 (Rw=0.056) for 3082 observed reflections, and toR=0.057 (Rw=0.075) for 1850 observed reflections for3, 4a·C6H5Cl and4e, respectively. The Fe-Zn complexes (9a), (9b) and (9c) were prepared and characterized by spectroscopic methods.

β-Keto phosphines derived from ferrocene. Syntheses and structures of [Ph2PCH2C(O)(η5-C5H4)Fe(η5-C5H5)] (L1) and trans-[PdCl2L12]

Abstract The keto-phosphines [Ph2PCH2C(O)(η5-C5H4)Fe(η5-C5H5)] (L1), [{Ph2PCH2C(O)(η5-C5H4)}2Fe] (L2) and [{Ph2PCH2C(O)(η5-C5H4)}Fe{(η5-C5H4)C(O)Ch3}] (L3) were respectively prepared by the reaction of Ph2PCl with the lithium enolates derived from acetylferrocene for L1, and 1, 1′-bis(acetyl)ferrocene for L2 and L3. Ligand L1 crystallizes in the space group P 1 with a 8.526(2), b 10.915(3), c12.822(3) A, α 63.75(2), β 69.04(2), γ 70.77(2)°, V 978.4 A3 and Z 2. The structure was solved and refined to R = 0.034 and Rw = 0.042. The C5-rings are eclipsed (3.2°) and the plane of the keto group forms a dihedral angle of 13.1° with the C5H4 plane. In the complexes cis- and trans-[PdCl2L12] (cis-1 and trans-1), [(o- C 6 H 4 CH 2 NMe 2 )Pd C1L1] (2), cis-[PtCl2L12] (3), and [AuC1L1] (4) the phosphine ligand(s) behave as P-monodentate(s). The structure of rans-1 has been determined by X-ray diffraction at −145°C. The complex crystallizes in the monoclinic space group P21/c with a 10.622(7), b 12.647(7), c 15.59(1) A, β 103.20(6)°, V 2039 A3 and Z = 2. The structure was solved and refined to R = 0.037 and Rw = 0.053. The palladium atom lies on a centre of symmetry and the PdP and PdCl bond lengths are respectively 2.314(1) and 2.287(1) A. The C5-rings of each ligand are slightly staggered (10.5°) and, as for L1, each keto group is almost parallel to the C5H4 plane (dihedral angle 8.9°). For the complex [CuL12)]BF4, NMR and IR solution spectroscopy has shown that there is a dynamic exchange between chelating and P-monodentate L1. The possibility of using L2 as a binucleating ligand was demonstrated by the preparation of the trinuclear complex [{( C 10 H 8 N)P dCl}2(μ-L2-P,P′)] (6). The enolato complexes cis-[ M{Ph 2 PCHC(O )(η5-C5H4)Fe(η5-C5H5)}2] (M = Pd (7, M = Pt (8)), and [(o- C 6 H 4 CH 2 NMe 2 )P d{Ph 2 PCHC(O )(η5-C5H4)Fe(η5-C5H5)}] (9) were prepared in high yield by the reaction of NaH with complexes 1, 3, and 2, respectively. Complex 9 reacts with dimethylacetylenedicarboxylate to yield the alkenyl complex [(o- C 6 H 4 CH 2 NMe 2 )P d{Ph 2 PCH[C(O)(η 5 -C 5 H 4 )Fe(η 5 -C 5 H 5 )](MeO 2 CCC CO2M (10), resulting from carboncarbon coupling between the P bound enolate-carbon atom and the alkyne. All the complexes were characterized by elemental analysis, and 1H and 31P{1H} NMR and IR spectroscopy.

Reactivity of phosphine-phosphinite complexes. synthesis and crystal structure of [{Ph2PCHC(O)Ph} Pd(μ-Ph2PO)]2

Abstract Treatment of cis-[MCl2PCHC(Ph)OPPH2}] (M = Pd, 1; Pt; 2) with 2 equivalents of KOH in dichloromethane yielded quantitatively the dinuclear complexes [M2{Ph2PCHC(O)Ph)}2{μ-(PH2PO)}2] (M = Pd, 3; Pt, 4). The reaction of KOH with the nickel analogue of 1 led to dissociation of the phosphorus ligands and gave Ni(OH)2. The structure of 3·toluene was established by an X-ray diffraction study. Crystals of 3·toluene belong to the space group P 1 with a = 12.76(1) A, b = 14.672(5) A, c = 18.657(9) A, α = 76.97(3)°, β = 68.24(5)°, γ = 75.82(5)°, V = 3110.1A3, and Z = 2. The structure has been refined for 4254 reflections with F2o > 3 σ(F2o to R = 0.033 and Rw = 0.041. The structure consists of two square planar palladium centers linked together by two Ph2PO bridges. The PdP(phosphine) bond length are 2.210(2) A and 2.218(2)A, and those of PdP(phosphinito) bonds 2.245(2) A and 2.235(2) A. The dihedral angle between the metal planes is 72.3° (1) and the six-membered metal ring is in a boat conformation. The PO bond lengths of 1.533(4) A and 1.528(4) A indicate some double bond character. Reaction of complex 1 with 2 equivalents of NaCo(CO)4 gave the trinuclear complex [{Ph2PCH=C(Ph)OPPh2} PtCo2(CO)7] (5). In contrast to 1 and 2, the complex 5 does not undergo hydrolytic cleavage of the phosphinite ligand, possibly for steric reasons. All the complexes were characterized by elemental analyses and IR, 31P NMR spectroscopy.

Bis-alkenyl complexes of nickel, palladium and platinum from co-ordinated phosphino-enolates: X-ray structures of (R,S)-cis-[Pd{Ph2PCH[C(O)Ph][MeO2CCC(CO2Me)]}2] and [(o-C6H4CH2NMe2)Pd{Ph2PC{C(O)Ph][(MeO2C)CC(H)(CO2Me)]}]

Three isomeric polyfunctional phosphine ligands may be generated by carbon–carbon coupling between enolato complexes of the type [Ln[graphic omittd])Ph}](M = Ni, Pd, Pt) and the alkyne MeO2CCCCO2Me; the thermal isomerisation of the (P, alkenyl) form either leads to a (P, alkyl) chelate or, after metal–carbon bond cleavage and H-shift, to a ligand rearrangement with regeneration of (P, O) co-ordination.

Structural and cobalt-59 nuclear magnetic resonance study of heterosite reactivities of alkynes in Ru–Co carbonyl–nitrosyl clusters

The reactions of the tetrahedral mixed-metal cluster [NEt4][RuCo3(CO)12]1 with [NO][BF4] afforded the nitrosyl-substituted cluster [RuCo3(CO)11(NO)]3 in high yield. The latter reacts with excess alkynes RC2R′ to give [RuCo3(CO)9(NO)(µ4-η2-RCCR′)](R = R′= Ph 4a; R = Ph, R′= H 4b; R = R′= H 4c)via specific insertion in a Co–Co bond, together with a small amount of the corresponding trinuclear cluster [RuCo2(CO)9(µ3-η2-RCCR′)](R = R′= Ph 5a; R = Ph, R′= H 5b; R = R′= H 5c). All the complexes have been characterised by IR, UV/VIS, 1H and 59Co NMR spectroscopy. The crystal structures of 3 and 4b have been determined by X-ray diffraction methods. Complex 3 exhibits a RuCo3 tetrahedron and the linear nitrosyl ligand is axially bonded to one of the Co atoms of the Co3 base. The structure of 4b consists of a RuCo3 butterfly in which the ruthenium atom occupies a hinge position, the alkyne ligand having been incorporated into the cluster core to generate a closo-RuCo3C2 octahedral framework.

Sulfur-capped cyclodextrins: a new class of cavitands with extroverted as well as introverted donor functionalities

Ansa-cyclodextrins were obtained in high yields by reaction of sodium sulfide with A,B-di- or A,B,D,E-tetramesylated alpha-CD precursors; the resulting thiocavitands are suitable for forming nanotubular molecules, as well as for hosting metal-organic fragments.