Oliver Struck

Spontaneous formation of a 1D-coordination polymer with helix structure starting from (S)-pyroglutamic acid and copper(II) acetate

Reaction of a methanolic copper(II) acetate solution and (S)-methoxycarbonyl pyrrolidine (6) (HL3) in the presence of triethylamine leads to a mixture of two charges of crystals that are easy to distinguish visually. According to X-ray crystal structure analyses the products are the pseudo dimeric molecular complex [CuL32]·[CuL42] (12) and the helical 1D-coordination polymer ([CuL32]·12Et2O)∞ (3). Prerequisite for the formation of the centrosymmetric complex 12 is the partial inversion of [(S),(S)-CuL32] (10) (HL3=6) to [(R),(R)-CuL42] (11) (HL4=7), induced by triethylamine. Complex 12 is formed via linking of monomers 10 and 11 across two of the four available MeO oxygens. The unit cell of the 1D-coordination polymer 3 is composed of two almost identical helix strands (Λ)-Cu(1)-3 and (Δ)-Cu(2)-3. Each strand is generated by a set of very similar monomeric building blocks Cu(1)-10 and Cu(2)-10. The structure data of (Λ)-Cu(1)-3 and (Δ)-Cu(2)-3, reveal that each of the Cu(1) and Cu(2) atoms is linked across the N(28) atoms of only one neighbouring cyano group of the monomers 10. The 1D-coordination polymer (Λ)-Cu(1)/(Δ)-Cu(2)-3 cocrystallises with diethyl ether to form a clathrate.

Eindimensionale Kupfer(II)-Koordinationspolymere: Kristall-Engineering durch variable Verknüpfungsmuster [1] / One Dimensional Copper(II) Coordination Polymers: Crystal Engineering through Variable Types of Linkage [1]

Reaction of a methanolic copper(II) acetate solution with tetrazolyl enol derivatives 2a or 2b leads to the formation of the corresponding lD-coordination polymer 1∞[CuL2] 3a and pseudo 1D-coordination polymer [CuL2]2 3b, respectively. On the contrary, reaction of 2c with methanolic copper(II) acetate solution yields OH-bridged 1D-coordination polymer 1∞[CuL2(MeOH)2 3c. Single-crystal X-ray diffraction of the supramolecular species 3 established unequivocally the structures of the stairlike coordination compounds. Reaction of a methanolic copper(II) acetate solution with amidotetrazole derivative 6 leads to the formation of the lD-coordination polymer 1∞ [CuL2] 7. The structure of 7 has been established by X-ray structure analysis

Verknüpfung koordinativ ungesättigter Kupfer(II)-Monomere via Cyano-versus Tetrazolyl-Donor/ Linkage of Coordinatively Unsaturated Copper(II) Monomers via Cyano versus Tetrazolyl Donor

Abstract Reaction of a methanolic copper(II) acetate solution with tetrazolyl enol derivatives 2a (HL2) or 2b (HL3) leads to the formation of the corresponding 2D-coordination polymers 4 (∞2 [CuL22]) and 5 (∞2 [CuL23]), respectively. Single-crystal X-ray diffraction of the supramolecular species 4 and 5 established unequivocally the structures of the regioisomeric coordination polymers. On the contrary, reactions of 2c (HL4) with methanolic copper(II) acetate solution and 2b (HL3) with methanolic zinc(II) acetate solution yield mononuclear chelate complexes 11 ([CuL42]) and 12 ([ZnL23(MeOH)2]). The structures of 11 and 12 have been established by X-ray structure analysis.

Synthese, Reaktivität und Struktur von Semicorrinatcobalt-Komplexen [1] / Synthesis, Reactivity and Structure of Cobalt Semicorrinate Complexes [1]

Abstract Recently we have shown that reaction of copper(II) acetate with pyrrolidines 3 (HL1) and 4 (HL2) leads to the formation of the 2D-coordination polymer 1 and the helical 1 D-polymer 2. Ligands of semicorrin type 9 (HL3-5) exhibit similar structural motives compared with the tridentate pyrrolidine ligands 3 and 4. Reaction of semicorrin 9a (HL3) with Co(II) acetate yields the mononuclear chelate complex 10a (CoL32), whereas in the presence of oxygen the formation of the oxidation product 14 [CoL32(OAc)] is observed. The chiral semicorrin ligands 9b, c (HL4, HL5) react with metal(II) acetates to give the complexes 10b,c-13b,c via diastereospecific complexation. The structures of the cobalt complexes have been established by single-crystal X-ray diffraction.

Synthese und Struktur diastereomerer, zweikerniger Kupferkomplexe [1] / Synthesis and Structure of Diastereomerie Dinuclear Copper Complexes [1]

Abstract Depolymerisation of a copper(II)/pyrrolidine-based 2D -polymer 2 by 4,4′-bipyridyl [molar ratio: 2 (CuL2) : 1 (Bipy)] and recrystallisation of the reaction product leads to two visually distinguishable crystal charges, composed of dark green octahedra meso-4 and light green rod-shaped crystals racem-5. Separation of the conglomerate of the morphologically different crystals is accomplished by pick out. The structure of the dinuelear complex racem-5 has been established unambigously by X-ray structure analysis. EPR and susceptibility measurements of mixtures of complex meso-4 and racem-5 indicate that there is no interaction between the two copper(II) centres.