2015, Dragutan, Ileana, Dragutan, Valerian, Simionescu, Bogdan C, Demonceau, Albert, Fischer, Helmut

This account critically surveys the field of side-chain transition metal-containing polymers as prepared by controlled living ring-opening metathesis polymerization (ROMP) of the respective metal-incorporating monomers. Ferrocene- and other metallocene-modified polymers, macromolecules including metal-carbonyl complexes, polymers tethering early or late transition metal complexes, etc. are herein discussed. Recent advances in the design and syntheses reported mainly during the last three years are highlighted, with special emphasis on new trends for superior applications of these hybrid materials.

2011, Reichmann, Bernhard, Drexler, Matthias, Weibert, Bernhard, Szesni, Normen, Strittmatter, Tobias, Fischer, Helmut

The reaction of the bis(amino)allenylidene complex [(CO)₅W═C═C═C(NMe₂)₂] with diethyldiazomethane yields two products, a cyclic carbene complex (2) by 1,2-addition of Et₂C−N₂ to the C_α−C_β bond of the allenylidene ligand and the η¹-butatriene complex [(CO)₅W{C[C(NMe₂)₂]═C═CEt₂}] (3). Complex 2 slowly eliminates N₂ and rearranges into 3. In contrast, only η¹-butatriene complexes, [(CO)₅M{C[C(NMe₂)XR]═C═C(R′)₂}], are isolated from the reaction of diazoalkanes (R′)₂C−N₂ (R′ = Me, Et, ⁿPr) with alkoxy(amino)allenylidene complexes [(CO)₅M═C═C═C(NMe₂)OR] (M = Cr, W; R = Me, Et, (−)-menthyl) or with the (alkylthio)(amino)allenylidene complex [(CO)₅W═C═C═C(NMe₂)SⁿPr]. These new η¹-butatriene complexes are related to C_α phosphine adducts of allenylidene complexes such as [(CO)₅W{C(PMe₃)═C═C(NMe₂)Ph}] (17) and might be regarded as C_α carbene adducts. However, the PMe₃ substituent in 17 is not replaced when 17 is treated with an N-heterocyclic carbene. Vice versa, the “carbene” substituent “C(NMe₂)OEt” in the η¹-butatriene complex [(CO)₅Cr{C[C(NMe₂)OEt]═C═CEt₂}] is not replaceable by PMe₃. Free N-heterocyclic carbenes do not add to the C_α atom of the allenylidene complex [(CO)₅W═C═C═C(C₆H₄NMe₂-p)₂] but instead to the C_γ atom, giving the dipolar neutral alkynyl complexes [(CO)₅W−C≡CC(C₆H₄NMe₂-p)₂L] (L = SIMe, SIMes). DFT calculations on the reaction mechanism indicate that a cyclic carbene complex and two isomeric η²-butatriene complexes are intermediates in the reaction pathway to form η¹-butatriene complexes. The structure of two representative examples of η¹-butatriene complexes and of one C_γ carbene adduct has been established by X-ray structure analyses.

2009, Haas, Thomas, Oswald, Stefan, Niederwieser, Andrea, Bildstein, Benno, Kessler, Florian, Fischer, Helmut

Bis(ferrocenyl)-substituted allenylidene complexes, [(CO)5MCCCFc2] (1a c, Fc = (C5H4)Fe(C5H5), M = Cr (a), Mo (b), W (c)) were obtained by sequential reaction of Fc2CO with Me3Si CCH, KF/MeOH, n-BuLi, and [(CO)5M(THF)]. For the synthesis of related mono(ferrocenyl)allenylidene chromium complexes, [(CO)5CrCCC(Fc)R] (R = Ph, NMe2), three different routes were developed: (a) reaction of the deprotonated propargylic alcohol HCCC(Fc)(Ph)OH with [(CO)5Cr(THF)] followed by desoxygenation with Cl2CO, (b) Lewis acid induced alcohol elimination from alkenyl(alkoxy)carbene complexes, [(CO)5CrC(OR)CHC(NMe2)Fc], and (c) replacement of OMe in [(CO)5CrCCC(OMe)NMe2] by Fc. Complex 1a was also formed when the mono(ferrocenyl)allenylidene complex [(CO)5CrCCC(Fc)NMe2] was treated first with Li[Fc] and the resulting adduct then with SiO2. The replacement route (c) was also applied to the synthesis of an allenylidene complex (7a) with a CC spacer in between the ferrocenyl unit and Cγ of the allenylidene ligand, [(CO)5CrCCC(NMe2)-CCFc]. The related complex containing a CHCH spacer (9a) was prepared by condensation of [(CO)5CrCCC(Me)NMe2] with formylferrocene in the presence of NEt3. The bis(ferrocenyl)-substituted allenylidene complexes 1a c added HNMe2 across the Cα Cβ bond to give alkenyl(dimethylamino)carbene complexes and reacted with diethylaminopropyne by regioselective insertion of the CC bond into the Cβ Cγ bond to afford alkenyl(diethylamino)allenylidene complexes, [(CO)5MCCC(NEt2)CMeCFc2]. The structures of 5a, 7a, and 9a were established by X-ray diffraction studies.

2008, Dragutan, Ileana, Dragutan, Valerian, Fischer, Helmut

2011-08, Kessler, Florian, Wuttke, Evelyn, Lehr, Daniela, Wang, Yan, Weibert, Bernhard, Fischer, Helmut

2010, Powala, Beata, Fischer, Helmut, Pietraszuk, Cezary

The first generation Grubbs catalyst [Cl2{P(C6H11)3}2Ru=C(H)Ph] reacts efficiently with alkynylsilanes in the presence of water to give the styryl carbene complex [Cl2{P(C6H11)}2Ru=C(CH=CHPh)H] and disiloxane.

2009, Kessler, Florian, Szesni, Normen, Põhako, Kaija, Weibert, Bernhard, Fischer, Helmut

Oxidative addition of BrCCC(=O)NR2 to [Pd(PPh3)4] affords the trans-alkynylbromopalladium complexes trans-[Br(PPh3)2Pd−CCC(=O)NR2] (NR2 = NMe2 (2a), N(CH2)4) (2b)). Subsequent reaction of 2a,b with PiPr3 in excess gives trans-[Br(PiPr3)2Pd−CCC(=O)NR2] (5a,b). The analogous reaction of 2b with P(C6H4OMe-4)3 gives trans-[Br(P{C6H4OMe-4}3)2Pd−CCC(=O)NR2] (7b), and that of 2a with trifluoroacetate gives trans-[(F3CCOO)(PPh3)2Pd−CCC(=O)NMe2] (9a). Methylation of 2a,b, 7b, and 9a with either MeOTf or [Me3O]BF4 and ethylation of 2a,b with [Et3O]BF4 yield the first cationic allenylidene complexes of palladium, trans-[R*(PR′3)2Pd−CCC(OMe)NR2]+X− (R* = Br, CF3COO; R′ = Ph, C6H4OMe-4, iPr; X = OTf, BF4).

2011-02, Haas, Thomas, Kaspar, Katrin, Forner, Konstanze, Drexler, Matthias, Fischer, Helmut

2010, Kessler, Florian, Weibert, Bernhard, Fischer, Helmut

2008, Pui, Aurel, Fischer, Helmut, Kopf, Henning

A series of R-Salophen manganese(III) and iron(III) complexes, where R = OH, OCH3 or COOH, and Salophen is bis(salicylaldehyde)-N,N’-o-phenylendiimine, have been obtained. The synthesis and characterization by elemental analyses, 1H NMR, UV-VIS, FT IR, ESMS spectroscopy and cyclic voltammetry of the ligands and some complexes of Mn(III) and Fe(III) with R-Salophen are presented in this study.