Winter, Rainer F.
Comparative biological evaluation of two ethylene linked mixednext term binuclear ferrocene/ruthenium organometallic species
2010, Ott, Ingo, Kowalski, Konrad, Gust, Ronald, Maurer, Jörg, Mücke, Philipp, Winter, Rainer F.
Two ethylene linkednext term binuclear previous termmixednext term ferrocene/ruthenium complexes were biologically investigated in comparison to structurally related mononuclear ferrocene or ruthenium species with styryl substituents or ligands. Results indicated that the electron distribution (but not the redox potential), cellular uptake and (to some minor extent) anti-estrogenic effects were the key contributors to antiproliferative effects observed in tumor cell lines.
Synthesis and electrochemical behavior of the ferrocenyl units assembled on imidoalane and carbaalane clusters
2005, Winter, Rainer F., Baldus, Marc, Andronesi, Ovidiu, Roesky, Herbert, Srisailam, Shravan Kumar
Hydroalumination reaction was effectively carried out on ferrocenylnitrile in the synthesis of imidoalane cluster [HAlNCH2C5H4FeCp]6 (3). Compound 3 exhibits a reversible electrochemical behavior. In the presence of ferrocenylmethanol, meta thesis reactions were carried out on [HAlNCH2(C4H3S)]6 (4) and [HAlNCH2Ph]6 (5) in the synthesis of [CpFeC5H4CH2OAlNCH2(C4H3S)]6 (6) and [CpFeC5H4CH2OAlNCH2Ph]6 (7). The ferrocenylmethoxide groups present in these two compounds show a single reversible oxidation wave, which suggests their electrochemical equivalence. Electrochemical studies were also carried out on the carbaalane [(AlH)2(FcCtriple bond; length of mdashCAl)4(AlNMe3)2(CCH2Ph)6] (9), which exhibited a considerably broadened wave with shoulders preceding the main anodic and cathodic peak, and it can be assigned to weak electronic interactions between the individual ferrocenyl sites.
Synthesis, solid state structure and spectro-electrochemistry of ferrocene-ethynyl phosphine and phosphine oxide transition metal complexes
2009, Jakob, Alexander, Ecorchard, Petra, Linseis, Michael, Winter, Rainer F., Lang, Heinrich
The synthesis of ferrocene-ethynyl phosphine platinum dichloride complexes based on (FcCtriple bond; length of mdashC)nPh3−nP (1a, n = 1; 1b, n = 2; 1c, n = 3; Fc = ferrocenyl, (η5-C5H5)(η5-C5H4)Fe) is described. Air-oxidation of 1c afforded (FcCtriple bond; length of mdashC)3Pdouble bond; length as m-dashO (6). Treatment of 1a–1c with [(PhCtriple bond; length of mdashN)2PtCl2] (2) or [(tht)AuCl] (tht = tetrahydrothiophene) (7), respectively, gave the heterometallic transition complexes cis-[((FcCtriple bond; length of mdashC)nPh3−nP)2PtCl2] (3a, n = 1; 3b, n = 2; 3c, n = 3) or [((FcCtriple bond; length of mdashC)nPPh3−n)AuCl] (8a, n = 1; 8b, n = 2). Further treatment of these molecules with HCtriple bond; length of mdashCMc (4a, Mc = Fc; 4b, Mc = Rc = (η5-C5H5)(η5-C5H4)Ru) in the presence of [CuI] produced trans-[((FcCtriple bond; length of mdashC)Ph2P)2Pt(Ctriple bond; length of mdashCFc)2] (5) (reaction of 3a with 4a) and [(FcCtriple bond; length of mdashC)nPh3−nPAuCtriple bond; length of mdashCMc] (n = 1: 9a, Mc = Fc; 9b, Mc = Rc; n = 2: 11a, Mc = Fc; 11b, Mc = Rc) (reaction of 4a, 4b with 8a, 8b), respectively.
The structures of 3a, 5, 6, 8, 9a, and 9b in the solid state were established by single-crystal X-ray structure analysis. The main characteristic features of these molecules are the linear phosphorus–gold–acetylide arrangements, the tetra-coordination at phosphorus and the square-planar surrounding at platinum.
The electrochemical and spectro-electrochemical behavior of complexes 5, 8a, 9a, 9b and [(Ph3P)AuCtriple bond; length of mdashCFc] was investigated in the UV/Vis/NIR. Near IR bands that are likely associated with charge transfer from the ((FcCtriple bond; length of mdashC)Ph2P)2Pt or the ((FcCtriple bond; length of mdashC)nPh3−nP)Au (n = 0, 1) moieties appear upon oxidation of the σ-bonded ferrocene-ethynyl groups. These bands undergo a (stepwise) blue shift as ferrocene-ethynyl substituents on the phosphine coligands are oxidized.
Allylferrocenylselenide and the synthesis of the first seleno-substituted allenylidene complex: synthesis, spectroscopy, electrochemistry and the effect of electron transfer from the ferrocenylselenyl subunit
2001, Hartmann, Stephan, Winter, Rainer F., Schiering, Thomas, Wanner, Matthias
Allylferrocenylselenide (2) is prepared from diferrocenyldiselenide (1Se) which was characterized along with its sulfur analog 1S by X-ray structure analysis. In the crystal lattice the packing is determined by ‘point-to-face’ CHcdots, three dots, centeredπ interactions with close contacts between the CH π donors and cyclopentadienyl rings as the π acceptors. Compound 2 is then used in the trapping of the primary butatrienylidene intermediate trans-[ClRu(dppm)2=C=C=C=CH2]+. The isolated product, trans-[Cl(dppm)2Ru=C=C=C(SeFc)(C4H7)]+ (3) (Fc=ferrocenyl), represents the first seleno-substituted allenylidene complex to be reported to date. Compound 3 is formed in a sequence involving regioselective addition of the selenium nucleophile to Cγ followed by hetero-Cope-rearrangement of the allyl vinyl substituted SeR3+ cation. Its spectroscopic properties place 3 at an intermediate position between sulfur and arene substituted all-carbon allenylidene complexes of the same metal fragment. The selenoallenylidene complex 3 contains a redox active ferrocenyl substituent attached to the heteroatom giving rise to reversible electrochemistry. ESR spectroscopy proves that electron transfer occurs from this site and its effect on the spectroscopic properties of 3 is probed by combining electrochemistry and IR or UV–vis/NIR spectroscopy by in situ techniques. In contrast, the reversible reduction primarily involves the allenylidene ligand as ascertained by ESR spectroscopy. In situ spectro-electrochemical techniques reveal how the reduction affects the bonding within the unsaturated ligand.
Fulvalenediyl-bridged heterobimetallic complexes consisting of sandwich and half-sandwich compounds with early–late transition metals
2009, Jakob, Alexander, Ecorchard, Petra, Rüffer, Tobias, Linseis, Michael, Winter, Rainer F., Lang, Heinrich
A straightforward synthesis methodology for the preparation of heterobimetallic [(η5-C5H5)(η5-C5H4-C5Me4)M] (3a, M = Fe; 3b, M = Ru) and [(η5-C5H5)((μ-η5:η5-C5H4-C5Me4)TiCl3)M] (4a, M = Fe; 4b, M = Ru) in which early and late transition metals are connected by a fulvalenediyl bridge is reported.
The structures of molecules 3b and 4a in the solid state are discussed. Most noteworthy in 4a is the exo arrangement of the iron and titanium atoms coordinated by the fulvalenediyl unit which itself is twisted with a dihedral angle between the joined cyclopentadienyl rings of 19.33(9)°. Electrochemical, UV/Vis/NIR spectroscopic and spectroelectrochemical experiments on 4a and Cp*TiCl3, for comparison, provide evidence for some transfer of electronic information between the conjoined ferrocene and half-sandwich titanocene trichloride subunits of 4a. Evidence comes from systematic potential shifts and the presence of a fairly intense Fe → Ti charge-transfer absorption band that vanishes upon oxidation and reduction of 4a.