The reaction of (//5-C ,H 4SiM e3)2TiC b (1) with H O (C H ^)„C =C R (2a: n = 1, R = H; 2b: n = 1, R = C H 3; 2c: n = 1, R = C H 2O H; 3: n = 2, R = H; 4: n = 4, R = H) affords in toluene at 25 °C in the presence of N E t3 the m onoalkyne-ol substituted titanocenes (/75-C5H 4SiM e3)2T i(C l)[0 (C H ,)„C = C R ] (5a: n = 1. R = H; 5b: n = 1, R = C H 3; 5c: n = 1, R = C H 2O H: 6: n = 2, R = H; 7: n = 4. R = H). Com pound 5 c reacts with one equivalent of 1 in the presence of N E t3 to yield (?75-C5H 4SiMe3)2(C l)T i-0 C H 2C = C C H 20-T i(C l)(?75-C5H 4SiM e3)2 (8). In addition, com ­ pound 8 can be synthesized directly by treatm ent of (rj5 C5H 4SiM e3)2TiCl2 (1) with 0.5 equi­ valents of H O C H 9C=CCH->OH (2c) in the presence of N E t3. The reaction of (775-C5H 4SiMe3)2Ti(C l)(O C H 7C = C C H 3) (5 b) with Co2(C O )8 (9) yields (?;5-C5H 4SiMe3)2Ti(Cl)[(?/2-O C H 2C = C C H 3)C o2(C O )6] (10). Treatm ent of 5b or 10 with H Cl(aq) (11) leads to the form ation of (7/5-C5H 4SiM e3)2TiCl2 (1) and H O C H 2C = C C H 3 (2b) (reaction of 5b with 11) or (?75-C5H 4SiM e3)2TiCl2 (1) and [(?/2-H O C H 2C = C C H 3)C o2(C O )6] (12) (reaction of 10 with 11). All com pounds have been characterized by analytical and spectroscopic data (IR , ’H, 13C NM R, MS) and (^5-C5H4SiM e3)2T i(C l)(O C H 2C = C C H 3) (5b) by X-ray analysis.

2,2 '-Bipyrimidine metal complexes with Ti, Mo, Fe, Ru, Pt, Ag, and Cu transition metal atoms have been synthesized and structurally characterized. These molecules were prepared by following synthesis methodologies. The reaction of 2,2 '-bipyrimidine (1; bipym) with {[Ti](mu-sigma,pi-C equivalent to CSiMe3)(2)}AgOTf([Ti] = (eta(5)-C5H4SiMe3)(2)Ti, OTf = OSO2CF3) (2) in a 1: 1 molar ratio gave [{[Ti](mu-sigma, pi-C equivalent to CSiMe3)(2)}Ag(bipym)]OTf (3) which on further treatment with another equivalent of 2 produced [({[Ti](mu-sigma, pi-C equivalent to CSi Me-3)(2)}Ag)(2)(mu-1,2,3,4-bipym)](OTf)(2) (4). As consequence thereof, the coordination number of Ag(I) was changed from 3 to 4. A platinum-bipym complex with two acetylide substituents was accessible by the gradual reaction of 1 with K-2[PtCl4] (5) and two equivalents of HC equivalent to CR (7a, R = SiMe3; 7b, R = Fc; 7c, R = Rc; Fc = (eta(5)-C5H4)(eta(5)-C5H5)Fe; Rc = (eta(5)-C5H4)(eta(5)-C5H5)Ru) in di-iso-propylamine and in presence of [Cul]. Originating from cis-[(bipym)Pt(C equivalent to CR)(2)] (8a, R = SiMe3; 8b, R = Fc; 8c, R = Rc) diverse multinuclear complexes with two, three or four different transition metals could be obtained. These are: [((CO)(4)Mo)(mu-1,2,3,4-bipym)Pt(C equivalent to CFc)(2)] (10), [(AgClO4)(mu-1,2,3,4-bipym){[Pt(mu-sigma,pi-C equivalent to CFc)(2)]AgO-ClO3}] (12), [(McC equivalent to C)(2)Pt(mu-1,2,3,4-bipym)({[Ti](mu-sigma,pi-C equivalent to CSiMe3)(2)}M)]X (15a, Mc = Fc, M = Cu, X = PF6; 15b, Mc = Rc, M = Cu, X = PF6; 15c, Mc = Fc, M = Ag, X = ClO4), and [(McC equivalent to C)(2)Pt(mu-1,2,3,4-bipym) PtCl2] (17). Like other organometallic Pt - Ag tweezer complexes, compound 12 decomposed to give FcC equivalent to C-C equivalent to CFc (13). During prolonged stirring of 15a and 15b, respectively, [(McC equivalent to C)(2)Pt(mu-1,2,3,4- bipym)({[Ti](mu-sigma,pi-C equivalent to CSiMe3)(mu-sigma,pi-C equivalent to CH)}M)]X (15'a, M = Cu, X = PF6; 15'b, M = Cu, X = PF6) was formed.The structures of 8b, 8c, 15a', and 15b' in the solid state are reported. All complexes exhibit the anticipated planar dinuclear Pt - M structure ( M = Pt, Cu, Ag) with the 2,2'-bipyrimidine unit in a l- 1,2,3,4- bridging mode.Electrochemical investigations were carried out with 8a, 8b, and 8c and show that no significant influence of R on the bipym redox potentials exists. The typical redox behavior for the bipym, ferrocene, ruthenocene units and platinum were observed. (C) 2008 Elsevier B. V. All rights reserved.

The synthesis and characterisation of a new highly active Hoveyda-Grubbs 2nd generation type catalyst is described. Substitution of one chloride ligand with a partially fluorinated trialkoxysilyl substituted carboxylate leads to the stable monocarboxylate ruthenium catalyst (3). This catalyst represents the first example of a stable and isolable mono-chloride exchanged carboxylate complex suitable for both homogeneous and heterogeneous metathesis. The reactivity of the new catalyst was tested in representative metathesis reactions and offers an activity comparable to the parent dichloride system (1). (c) 2006 Elsevier Ltd. All rights reserved.

The selective exchange of one or both chloride ligands in the Hoveyda-Grubbs first and second generation catalysts with partially fluorinated trialkoxysilyl-containing silver(I) carboxylates has been achieved. This gives access to ruthenium catalysts which can be used both homogeneously or immobilized on silica. The synthesis and reactivity of these complexes are described including the monocarboxylate ruthenium catalysts [RuCl((RO)3Si–C3H6–N(R′)–CO–C3F6–COO)(CH–o-O–iPr–C6H4)(SIMes)] (R=Et, R′=H and R=R′=Me).

Partly fluorinated trialkoxysilyl-substituted carboxylic acids (RO)(3)Si(CH2)(3)N(R')C(O)(CF2)(3)COOH (3a: R = Et, R' = H; 3b: R = R' = Me) have been prepared in a straightforward synthesis from the respective trialkoxysilyl-substituted primary and secondary amines and hexafluoroglutaric anhydride. Treatment with silver(I) oxide yields the corresponding silver carboxylates 4a, b which have been thoroughly characterized in solution and in the solid state, including an X-ray crystallographic analysis of 4a. The molecular structure of 4a consists of archetypal carb oxylate-bridged disilver(I) pairs with a strong closed-shell Ag-Ag (d(10)-d(10)) interaction and a unique intramolecular bond between a silyl ether group and the metal ion. In addition the amide oxygen atoms are involved in H-bonding and in intermolecular silver coordination, giving rise to an unusual two-dimensional network structure. Silyl-free acid iPr(2)NC(O)(CF2)(3)COOH (5) and its silver salt 6 have been prepared and structurally characterized for comparison. It is shown that the trialkoxysilyl tail in 4a, b allows for convenient attachment of these silver complexes to silica surfaces, as is corroborated by DRIFT measurements. The immobilized silver carboxylates 7a, b exhibit remarkable stability and are expected to open an easy access to a wide variety of SiO2,grafted transition metal catalysts via transfer of the carboxylate ligand in simple exchange reactions. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005).

Silver(I) and rhodium(I) complexes bearing the bisallyl-substituted N-heterocyclic carbene ligand (4R,5S)-4,5-diallyl-1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene (allyl(2)SIMes) have been prepared in a straightforward synthesis. The reaction of (4R,5S)-4,5-diallyl-1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydro-3H-imidazol-1-ium tetrafluoroborate (la) with Ag2O affords the ionic biscarbene complex [(allyl(2)SIMes)(2)Ag]+BF4- (2), while the reaction of (4R,5S)-4,5-diallyl-1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydro-3H-imidazol-1-ium chloride (1b) with Ag2O leads to the monocarbene complex (allyl(2)SIMes)AgCl (3). Sequential treatment of la with KOtBu and dimeric [RhCl(cod)](2) (cod = cyclooctadiene) yields the rhodium carbene complex (allyl(2)SIMes)RhCl(cod) (4). However, the reaction of la with the first-generation Grubbs catalyst (PCy3)(2)Cl2Ru=C(H)Ph (Cy = cyclohexyl) leads to ring-closing metathesis of the two allylic groups, yielding 1,3-bis(2,4,6-trimethylphenyl)-3a,4,7,7a-tetrahydro-3H-benzimidazol-1-ium tetrafluoroborate (5). Subsequent reaction of this new imidazolium salt with KOtBu and 1 equiv of (PCy3)Cl2Ru=C(H)(C(6)H(4)OiPr-2) forms [1,3-bis(2,4,6-trimethylphenyl)-3a,4,7,7a-tetrahydro-3H-benzimidazolin-2-ylidene]dichloro(2-isopropanolatoben- zylidene)ruthenium(II) (8). All new complexes have been thoroughly characterized, including X-ray crystallographic analyses of 2, 3, and 8. The most intriguing feature of 8 is the presence of an innocent C=C bond that is part of a highly active olefin metathesis catalyst, which offers many options for further functionalization of the ligand backbone. The catalytic activity of complex 8 has been evaluated for the ring-closing metathesis of N,N-diallyl-4-toluene-sulfonamide.

The synthesis of the heterobimetallic hafnium(IV)-nickel(0) complexes {[Hf](mu-sigma,pi-CdropCR)(2)}Ni(CO) (3a, [Hf] = (eta(5)-C5H5)(2)Hf, R = Ph; 3b, [Hf] = (eta(5)-C5H4SiMe3)(2)Hf R = Bu-t) in which an early (Hf) and a late (Ni) transition metal atom are bridged by sigma- and pi-bound alkynyl groups succeeds by treatment of [Hf](CdropCR)(2) (1a, [Hf] = (eta(5)-C5H5)(2)Hf, R = Ph; 1b, [Hf] = (eta(5)-C5H4SiMe3)(2)Hf, R = Bu-t) with equimolar amounts of Ni(CO)(4) (2). The reaction chemistry of 1 and 3 towards different substrates is discussed. Treatment of 3b with P(OMe)(3) (4a) affords the mononuclear nickel monocarbonyl complex Ni(CO)[P(OMe)(3)](3) (5), while the reaction of 1a or 1b with MCl2 (6a, M = Fe; 6b, M = Ni; 6c, M = Co) produces by an cyclopentadienyl transfer from hafnium to M the sandwich compounds (eta(5)-C5H4R')(2)M (M = Fe: 7a, R' = H; 7b, R' = SiMe3; M = Ni: 7c, R' = H; 7d, R' = SiMe3; M = Co: 7e, R' = H). Addition of KOH to 1b or 3b, respectively, affords the homobimetallic hafnium complex {[Hf](CdropCR)}(2)O (8) in which two [Hf](CdropCR) fragments are bridged by an oxygen atom. Possible reaction mechanisms for the formation of 5, 7 and 8 by starting from 1 or 3 will be given. The result of the X-ray structure analysis of 8 is reported. Complex 8 crystallises in the monoclinic space group C2/c with the cell parameters a = 24.437(8), b = 14.655(5), c = 14.123(4) Angstrom, beta = 101.67(2)degrees, V = 4953(3) Angstrom(3), Z = 4 and D = 1.454 g cm(-3). Complex 8 contains a linear Hf-O-Hf unit with pseudo-tetrahedral coordinated hafnium atoms.

The synthesis of the heterobimetallic hafnium(IV)-nickel(0) complexes {[Hf](μ-σ,π-C≡CR) 2 }Ni(CO) (3a, [Hf] = (η 5 -C 5 H 5 ) 2 Hf, R = Ph; 3b, [Hf] = (η 5 -C 5 H 4 SiMe 3 ) 2 Hf, R = t Bu) in which an early (Hf) and a late (Ni) transition metal atom are bridged by σ- and π-bound alkynyl groups succeeds by treatment of [Hf](C≡CR) 2 (la, [Hf] = (η 5 -C 5 H 5 ) 2 Hf, R = Ph; 1b, [Hf] = (η 5 -C 5 H 4 SiMe 3 ) 2 Hf, R = t Bu) with equimolar amounts of Ni(CO) 4 (2). The reaction chemistry of 1 and 3 towards different substrates is discussed. Treatment of 3b with P(OMe) 3 (4a) affords the mononuclear nickel monocarbonyl complex Ni(CO)[P(OMe) 3 ] 3 (5), while the reaction of la or 1b with MCl 2 (6a, M = Fe; 6b, M = Ni; 6c, M = Co) produces by an cyclopentadienyl transfer from hafnium to M the sandwich compounds (η 5 -C 5 H 4 R') 2 M (M = Fe: 7a, R' = H; 7b, R' = SiMe 3 ; M = Ni: 7c, R' = H; 7d, R' = SiMe 3 ; M = Co: 7e, R' = H). Addition of KOH to 1b or 3b, respectively, affords the homobimetallic hafnium complex {[Hf](C≡CR)} 2 O (8) in which two [Hf](C≡CR) fragments are bridged by an oxygen atom. Possible reaction mechanisms for the formation of 5, 7 and 8 by starting from 1 or 3 will be given. The result of the X-ray structure analysis of 8 is reported. Complex 8 crystallises in the monoclinic space group C2/c with the cell parameters a = 24.437(8), b = 14.655(5), c = 14.123(4) A, β = 101.67(2)°, V = 4953(3) A 3 , Z = 4 and D = 1.454 g cm - 3 . Complex 8 contains a linear Hf-O-Hf unit with pseudo-tetrahedral coordinated hafnium atoms.

N,N-Dimethylnaphthylamin (1) reacts with Butyllithium to give Li(Et2O)C10H6NMe2-8 (2). The reaction of 2 with Et2AlCl and EtAlCl2 yields Et2AlC10H6NMe2-8 (3) and EtAl(C10H6NMe2-8)(2) (5), respectively; reaction with (Bu2AlCl)-Bu-i yields (Bu2AlC10H6NMe2)-Bu-i-8 (4). 1 reacts with Me3Al to give the corresponding adduct Me3Al<--N(C10H7)Me-2 (6). LiCH2C6H4NMe2-2 (7), LiC6H4CH2NR2-2 (R = Me (10), Et (12)) react with Me2AlCl, Et2AlCl and iBu(2)AlCl under formation of R2AlCH2C6H4NMe2-2 (R = Me (8), Et (9)), (Bu2AlC6H4CH2NMe2)-Bu-i-2 (11) and Et2AlC6H4CH2NEt2-2 (13), respectively. The new compounds were characterized by elemental analyses, H-1-, C-13-, and Al-27-NMR spectroscopy, and mass spectrometry, the structures of 3 (two modifications), 5, and 6 were determined by single crystal X-ray diffraction.

Abstract The synthesis of the heterobimetallic hafnium(IV)-nickel(0) complexes {[Hf](μ-σ ,π- C≡CR)2}Ni(CO) (3a, [Hf] = (η5-C5H5)2Hf, R = Ph; 3b, [Hf] = (η5-C5H4SiMe3)2Hf, R = tBu) in which an early (Hf) and a late (Ni) transition metal atom are bridged by σ - and π-bound alkynyl groups succeeds by treatment of [Hf](C≡CR)2 (1a, [Hf] = (η5-C5H5)2Hf, R = Ph; 1b, [Hf] = (η5-C5H4SiMe3)2Hf, R = tBu) with equimolar amounts of Ni(CO)4 (2). The reaction chemistry of 1and 3towards different substrates is discussed. Treatment of 3bwith P(OMe)3 (4a) affords the mononuclear nickel monocarbonyl complex Ni(CO)[P(OMe)3]3 (5), while the reaction of 1aor 1bwith MCl2 (6a, M = Fe; 6b, M = Ni; 6c, M = Co) produces by an cyclopentadienyl transfer from hafnium to M the sandwich compounds (η5-C5H4R’)2M (M = Fe: 7a, R’ = H; 7b, R’ = SiMe3; M = Ni: 7c, R’ = H; 7d, R’ = SiMe3; M = Co: 7e, R’ = H). Addition of KOH to 1b or 3b, respectively, affords the homobimetallic hafnium complex {[Hf](C≡CR)}2O (8) in which two [Hf](C≡CR) fragments are bridged by an oxygen atom. Possible reaction mechanisms for the formation of 5, 7and 8by starting from 1or 3will be given. The result of the X-ray structure analysis of 8is reported. Complex 8crystallises in the monoclinic space group C2/c with the cell parameters a = 24.437(8), b = 14.655(5), c = 14.123(4) Å, β = 101.67(2)◦, V = 4953(3) Å3, Z = 4 and D = 1.454 g cm−3. Complex 8contains a linear Hf-O-Hf unit with pseudo-tetrahedral coordinated hafnium atoms.

The hydroalumination of the allyl ethers CH2=CHCH2OR with (Bu2AlH)-Bu-i yields the (3-alkoxypropyl)diisobutylaluminum complexes (Bu2Al)-Bu-i(CH2)(3)OR (R = Me (1), Et (2), Bu (3)). Et2AlCl and (Bu2AlCl)-Bu-i react with (2-(methoxymethyl)phenyl)lithium and (2-methoxybenzyl)magnesium chloride, yielding (2-(methoxymethyl)phenyl)diethylaluminum (4), (2-(methoxymethyl)phenyl)diisobutylaluminum (5), and (2-methoxybenzyl)diisobutylaluminum (7), respectively. The reaction of (Bu2AlCl)-Bu-i with (2-methoxyphenyl)lithium affords the dimeric bis((2-methoxyphenyl)diisobutylaluminum) (6). Et2AlCl and (8-ethoxynaphthyl)lithium form (8-ethoxynaphthyl)diethylaluminum (10) along with a few crystals of bis(8-ethoxynaphthyl)aluminum chloride (13). AlCl3 reacts with 2 equiv of (2-methoxybenzyl)magnesium chloride, yielding bis(2-methoxybenzyl)aluminum chloride (9). Ligand redistribution followed by metathesis was observed for the reactions of Me2AlCl and Et2AlCl with (2-methoxybenzyl)magnesium and (8-methoxynaphthyl)lithium, yielding bis(2-methoxybenzyl)methylaluminum (8), bis(8-methoxynaphthyl)methylaluminum (11), and bis(8-methoxynaphthyl)ethylaluminum (12), respectively. The new compounds have been characterized by elemental analysis, NMR spectroscopy, and mass spectrometry. The solid-state structures of 6, 8, 9, and 11-13 were determined by single-crystal X-ray diffraction. The new aluminum alkyls are very active cocatalysts in the TiCl4-catalyzed ethylene polymerization. 7 and 10 cause a higher productivity compared to the common cocatalyst Al2Et6. The activity depends strongly on the structure of the oxygen-stabilized aluminum alkyls and is also influenced by the Al/Ti ratio.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The synthesis, characterization, and thermal behavior of the dicopper(l) oxalate complexes L2Cu2O4C2 (L = Me(3)SiCdropCSiMe(3) (1), Me(3)SicdropC(n)Bu (2), EtCdropCEt (3), H2C(H)(SiMe2Bu)-Bu-t(4), H2C=C(H)SiEt2Me (5), norbornene (6)) is reported. All complexes can be prepared in a straightforward manner by the reaction of stoichiometric amounts Of Cu2O and oxalic acid with 2 equiv of the respective alkyne or alkene. The complexes are stable at room temperature, and in solid form they can be handled in air for some time. Their thermal behavior was studied by thermal gravimetric analysis (TGA). The order of thermal stability was found to be 1 > 6 > 4 > 2 approximate to 3 > 5. Decomposition starts between 50 and 100degreesC and is completed between 300 and 350degreesC. All compounds fully decompose via an efficient internal redox process to give elemental copper, CO2, and the free alkyne or alkene ligands, which makes these new complexes promising precursors for copper deposition (in the case of 4, it is likely that H2C=C(H)SiMe2H and isobutene is formed via-hydrogen elimination from H2C=C(H)(SiMe2Bu)-Bu-t). Distinct two- or three-step decomposition sequences for the individual complexes are revealed by the TGA analyses and are discussed. The single-crystal X-ray structures of I and 3 are reported, which are the first for copper(I)/oxalato compounds. Both complexes exhibit the anticipated planar dinuclear structure with the oxalate in a mu-1,2,3,4 bridging mode and the alkynes or alkenes as capping ligands.