Synthesis and crystal structure of N,N'-diallyl-N,N,N',N'-tetramethylethylenediammonium (dalltmen2+) compounds: {dalltmen}(ClO4)2 and the copper(I) nitrate π-complex [{dalltmen}0.5Cu(NO3)2]


Chem. Met. Alloys 5 (2012) 90-97




N,N'-diallyl-N,N,N',N'-tetramethylethylenediammonium dichloride ({dalltmen}Cl2) was synthesized from N,N,N',N'-tetramethylethylenediamine (obtained by the Eschweiler-Clarke reaction of ethylenediamine, formaldehyde and formic acid) and allyl chloride. Then an ethanol solution of KOH was added to replace the Cl anions by OH ones and N,N'-diallyl-N,N,N',N'-tetramethylethylenediammonium dihydroxide ({dalltmen}(OH)2) was obtained. Single crystals of {dalltmen}(ClO4)2 (I) and the π-complex [{dalltmen}0.5Cu(NO3)2] (II) were obtained from alcohol solutions containing the hydroxide of the tetramethylethylenediamine diallyl derivative, previously titrated by HClO4 (or HNO3), and Cu(ClO4)2∙6H2O (or Cu(NO3)2·3H2O) by ac-electrochemical synthesis on copper wire electrodes. The structures of compounds I and II were determined by X-ray diffraction. Crystals I are orthorhombic: space group Pbca, Z = 4, a = 11.4125(6), b = 10.4604(5), c = 15.2884(8) Å, V = 1825.1(2) Å3. The structure consists of N,N'-diallyl-N,N,N',N'-tetramethylethylenediammonium cations and ClO4 anions, which are held together by electrostatic interactions and hydrogen bonds. Crystals II are monoclinic: space group P21/c, = 4, = 7.9620(4), = 8.2823(4), = 15.6224(8) Å, β = 96.793(2), = 1022.97(9) Å3. The structure contains infinite anionic chains (Cu(NO3)2)n with only one independent metal atom. The C=C bonds of the centrosymmetric N,N'-diallyl-N,N,N',N'-tetramethylethylenediammonium cation are π-coordinated by Cu(I) atoms from parallel inorganic fragments, so that the dalltmen2+ moities play a bridging role, connecting separate (Cu(NO3)2)n polymeric chains into layers (coordination nets). A branched system of hydrogen bonds connects the nets into a framework.



Fragment of crystal structure II



N,N'-diallyl-N,N,N',N'-tetramethylethylenediammonium cation / Anionic chains / Copper(I) nitrate π‑complex / Hydrogen bonds