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Neutral and cationic titanium and zirconium diamine bis(phenolate) complexes supported by chiral ligands L1and L2are described [L1= (R)‐6,6′‐{1‐(dimethylamino)propan‐2‐ylazanediyl}bis(methylene)‐bis(2,4‐di‐tert‐butylphenolate);L2= (S)‐6,6′‐{(1‐ethylpyrrolidin‐2‐yl)methylazanediyl}bis(methylene)‐bis(2,4‐di‐tert‐butylphenolate)]. Complexes[TiL(OiPr)2] [L = L1(1), L2(2)], [TiL2X(OiPr)] [X = Cl (3), CH2Ph (4)], [TiL1(CH2Ph)2] (5), [ZrLCl2] [L = L1(6), L2(7)] and [ZrL(CH2Ph)2] [L = L1(8), L2(9)] are C1‐symmetric species readily prepared in moderate to high yields. Cationic compounds were obtained from complexes 5, 8and 9through reactions with B(C6F5)3. The monocationic species reveal the η2‐binding character of the benzyl groups and noncoordinated [B(C6F5)3(CH2Ph)]–. Complexes 5–9were tested in the polymerization of ethylene and propylene upon activation with modified methylaluminoxane (MMAO), B(C6F5)3or [NHMe2Ph]+as cocatalysts. The [ZrL1Cl2]/MMAO and [ZrL1(CH2Ph)2]/B(C6F5)3systems revealed high activities in the polymerization of propylene (2.1 × 103and 1.5 × 103gpolmmolcat–1h–1, respectively), leading to atatic polypropylene, whereas the titanium complexes showed no activity.

The preparation of new chargetransfer CT salts based on the decamethylmetallocenium donors D, [MCp2] M = Mn, Cr, and on the bis[bistrifluoromethylethylene diselenolato]metalateIII acceptors A, [M′tds2] M = Ni, Pt, yielded four new members of the family of CT salts [MCp2][M′tds2] {MM′ = FeNi 1, FePt 2, MnNi 3, MnPt 4, CrNi 5, CrPt 6}. Their crystal structures consist of anarrangement of parallel mixed chains, DADADA, with short D–A contacts and large interchain separations. The CT salts 1–5are isostructural and 6shows minor differences in the interchain arrangements. The analysis of the intermolecular contacts, in the framework of the McConnell I model, provides a fair interpretation of the magnetic coupling. The behavior of these salts is dominated by the ferromagnetic FM D–A intrachain interactions. Coexisting weaker antiferromagnetic AF interchain couplings induce AF transitions in 2, 3, 4, and 6, with TN= 3.3, 2.1, 5.8, and 5.2 K, respectively. The intrachain coupling and the TNvalues of the CT salts based on the [MCp2] M = Fe, Mn donors 1, 2, 3, and 4 were found to be in good agreement with those predicted by the mean field model. Compounds 5and 6exhibit weaker intrachain coupling and lower critical temperatures than those predicted by that model, which is attributed to weaker D–A interactions. The study of the low temperature behavior of the salts 3, 4, and 6allowed the disclosure of the effect of the magnetic anisotropy of the donors. The CT salts based on highly anisotropic donors, such as 3and 4, show metamagnetic MM behavior, with phase diagrams that include a paramagnetic PM and an AF phase, as previously observed for 2. In the phase diagram of 6, where the [CrCp2] donor does not show magnetic anisotropy, a spinflop SF phase is present in addition to the PM and AF phases. This is the first time an SF phase was observed in [MCp2]based CT salts. © WileyVCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008

A series of ionic pseudo-octahedral trans-hydrido(nitrile)iron(II) complexes with the general formula [Fe(H)(dppe)2(4-NCR)][PF6] [dppe = 1,2-bis(diphenylphosphanyl)ethane; R = acceptor-substituted conjugated ligand] have been synthesised by chloride abstraction from the starting compound trans-[FeHCl(dppe)2] and fully characterised. First hyperpolarisabilities (β) have been determined by hyper-Rayleigh scattering (HRS) at the fundamental wavelength of 1072 nm and the high near-resonant values obtained (up to 1130 × 10–30 esu) are interpreted in terms of the two-level model (TLM) and are correlated with IR and NMR spectroscopic data. Wavelength-dependent HRS has been performed in the 1072–1580 nm range for two of the compounds, namely [Fe(H)(dppe)2{4-NC(CH)(CH)C6H4NO2}][PF6] and [Fe(H)(dppe)2{4-NCC6H4(CH)(CH)C6H4NO2}][PF6]. These results clearly show the two-photon resonance but also the shortcomings of the TLM when it comes to deriving reliable static β values. A structural study of the compound [Fe(H)(dppe)2(4-NCC6H4NO2)][PF6] by X-ray diffraction shows that it crystallises in the centrosymmetric monoclinic space groupP21/n, with four molecules in the unit cell and a pairwise antiparallel alignment of the dipoles. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Several sal2en-type reduced Schiff bases have been prepared from the reaction of 2 equiv. of salicylaldehyde (or derivatives) with ethylenediamine followed by reduction with NaBH4 and subsequently characterised. The water-soluble ligands (SO3-sal)2en and R(SO3-sal)2en (SO3-sal = salicylaldehyde-5-sulphonate) have been studied by pH potentiometry and 1H NMR spectroscopy and the protonation constants of R(SO3-sal)2en have been determined. The Schiff bases are more susceptible to hydrolysis than the corresponding reduced Schiff bases. The crystal structures of H2(o-van)2en and KH(o-van)2en (o-van = o-vanillin) have been determined by X-ray diffraction. The vanadium(IV) complexes have been prepared and characterised by magnetic measurements and IR, UV/Vis and EPR spectroscopy. The colours, magnetic susceptibilities and IR spectra of the new vanadium(IV) complexes of the reduced Schiff bases now obtained suggest oligomeric/polymeric structures for the compounds while the corresponding VIVO–Schiff-base complexes are monomeric.The complexation of [VIVO]2+ and [VVO2]+ with R(SO3-sal)2enin aqueous solution has been studied by pH potentiometry, UV/Vis as well as by EPR spectroscopy for the VIVO system and 1H and 51V NMR spectroscopy for the VVO2 system. Complex formation constants have been determined and binding modes have been proposed. N,N′-ethylenebis(pyridoxylaminato) (Rpyr2en) has also been obtained and the structure of Na[VVO2(Rpyr2en)]·CH3OH·3H2O determined by X-ray diffraction. The Rpyr2en2– ligand coordinates through both the N-amine and O-phenolate moieties in a symmetrical α-cis type coordination mode, i.e. with both O-phenolato donors cis to the O-oxo atoms and trans to each other. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)