Stressabbau: Selbstorganisierte Monoschichten aromatischer Moleküle zeigen eine wesentlich bessere Ordnung, wenn als Ankergruppe Selen‐ statt Schwefelatome verwendet werden. Vermutlich führt eine geringere Korrugation der Au‐Se‐Wechselwirkung dazu, dass die Moleküle leichter Strukturen annehmen, die von den aromatischen Grundgerüsten vorgegeben werden.

We developed convenient synthetic routes for the preparation of para-benzene disulfonic acid (H(2)BDS) and its tetrachloro (H(2)BDSCl(4)) and tetrafluoro (H(2)BDSF(4)) derivatives. The reaction of these acids with zinc nitrate in DMF led to single crystals of [Zn(BDS)(DMF)(2)] (triclinic, P ̄1[combining macron], Z=2, a=976.62(4), b=986.85(4), c=1014.40(4), α=69.106(2)°, β=68.746(2)°, γ=86.295(2)°, wR(2)=0.0627), [Zn(BDSCl(4))(DMF)(4)] (triclinic, P ̄1[combining macron], Z=1, a=831.5(1), b=905.2(1), c=989.6(1), α=90.44(2)°, β=91.41 (2)°, γ=106.72(2)°, wR(2)=0.0635), and [Zn(BDSF(4))(DMF)(4)] (monoclinic, P2(1)/c, Z=2, a=889.01(3), b=968.91(3), c=1633.07(5) pm, β=106.524(2)°, wR(2)=0.0948). While [Zn(BDS)(DMF)(2)] exhibits a layer structure, the disulfonate linkers connect the zinc ions into chains in the crystal structures of [Zn(BDSCl(4))(DMF)(4)] and [Zn(BDSF(4))(DMF)(4)]. Thermoanalytical investigations revealed that desolvation of the compounds occurs in a temperature range between 100 and 200 °C. The solvent free sulfonates show remarkably high stabilities, [Zn(BDS)(DMF)(2)] is stable up to nearly 600 °C. The halogenated acids were also used to prepare copper salts from aqueous solutions and Cu(2)(OH)(2)(CO(3)) (malachite) as a copper source. The crystal structure of [Cu(H(2)O)(6)](BDSF(4)) (triclinic, P ̄1[combining macron], Z=1, a=510.45(2), b=744.68(3), c=1077.77(4) pm, α=85.627 (2)°, β=77.449 (2)°, γ=76.015 (2)°) exhibits complex cations and uncoordinated sulfonate anions, while in [Cu(BDSCl(4))(H(2)O)(4)] (orthorhombic, Pnma, Z=4, a=721.27(2), b=2147.81(6), c=979.42(3) pm) the Cu(2+) ions are linked to infinite chains in the crystal structure. The most interesting structural feature of [Cu(BDSCl(4))(H(2)O)(4)] is the significant deviation from planarity of the disulfonate dianion. Theoretical investigations revealed that a boat conformation is favoured due to steric hindrance in cases where a syn coordination of the sulfonate groups occurs. The thermal behaviour of the copper compounds was also investigated by DTA/TG measurements and X-ray powder diffraction.

No abstract

The reaction of benzene 1,3,5-trisulfonic acid (H 3 BTS) with the hydroxides RE(OH) 3 (RE = La, Nd, Sm, Eu) in aqueous solution afforded the sulfonates [La(BTS)(H 2 O) 5 ] and [RE(BTS)(H 2 O) 4 ] (RE = Nd, Sm, Eu). Single crystal investigations were performed for the lanthanum and the europium compound, respectively. [La(BTS)(H 2 O) 5 ] is triclinic [P1, Z = 2, a = 783.18(6) pm, b = 1056.94(8) pm, c = 1082.38(8) pm, α = 114.860(2)°, β = 96.655(3)°, γ = 104.402(3)°] whereas [Eu(BTS)(H 2 O) 4 ] exhibits monoclinic symmetry [P2 1 /n, Z = 4, a = 767.61(5) pm, b = 1730.2(1) pm, c = 1134.06(8) pm, β = 108.375(8)°]. Despite these crystallographic differences, the structural features of the lanthanum and europium compounds are very similar. They show the metal ions connected by BTS anions to layers that are

No abstract