20654-09-5Relevant academic research and scientific papers
An investigation of the formation mechanism of copper(II) carbodiimide
Liu, Xiaohui,Puspitosari, Hari,Dronskowski, Richard
, p. 121 - 125 (2010)
The formation mechanism of copper(II) carbodiimide in aqueous ammonia solution was studied by synthetic and crystallography means. The reduction of the starting CuII solution led to the synthesis of solid Cu 1 intermediates, and the crystal structures of the two new compounds Cu(NCNH2)Cl (a = 8.2925(4), b = 3.7275(1), c = 12.4534(4) A, Pnma) and the isostructural Cu(NCNH2)Br (a = 8.406(3), b = 3.9229(9), c = 12.656(3) A, Pnma) were elucidated. A further increase in pH value by adding more ammonia led to the crystallization of two additional CuI intermediates, Cu2NCN and the ammine adduct Cu4(NCN) 2NH3. The former can be also made by the thermal decomposition of the latter whereas mild oxidation of Cu4(NCN) 2NH3 led to the formation of perfectly crystalline CuNCN.
A novel method for synthesizing crystalline copper carbodiimide, CuNCN. Structure determination by X-ray rietveld refinement
Liu, Xiaohui,Wankeu, Martial Aime,Lueken, Heiko,Dronskowski, Richard
, p. 593 - 596 (2005)
Well-crystallized copper carbodiimide, CuNCN, was synthesized by the slow oxidation of a copper(I) cyanamide precursor under aqueous conditions. The X-ray powder data evidence the orthorhombic system and space group Cmcm with a = 2.9921(1), b = 6.1782(1), c = 9.4003(2) ?, V = 173.769(5) ?3 and Z = 4. There is a strongly distorted octahedral Cu 2+ coordination reflecting a typical first-order Jahn-Teller effect, with interatomic distances of 4 x Cu-N = 2.001(2) ? and 2 x Cu-N = 2.613(3) ?; the NCN2- unit adopts the carbodiimide shape with C-N = 1.227(4) ?. Despite the formal d9 electron count of Cu2+, CuNCN exhibits a small temperature-independent paramagnetism and is likely to be a metallic conductor.
Monitoring surface transformations of metal carbodiimide water oxidation catalysts by operando XAS and Raman spectroscopy
Müller, Rafael J.,Lan, Jinggang,Lienau, Karla,Moré, René,Triana,Iannuzzi, Marcella,Patzke, Greta R.
, p. 10759 - 10766 (2018)
Transition metal carbodiimides MNCN (M = Co, Ni, Co0.9Ni0.1, Mn and Cu), were studied by simultaneous operando Raman and X-ray absorption spectroscopy (XAS) with focus on surface oxide detection during electrocatalytic water oxidation. As a proof of concept, easily modifiable screen-printed electrodes were used in this unified operando synchrotron setup for a trade-off between convenience of electrochemical anodization and spectroscopic data acquisition. Monitoring of chemical and structural transformations at the electrode surface during initial anodic electrode polarization shows stability for MNCN with M = Co, Ni, Co0.9Ni0.1 and Mn. While MnNCN is inactive, CoNCN emerges as the most active representative of the series. CuNCN displays pronounced side reactions and the formation of a surface copper oxide layer leading to lower current density attributed to water oxidation, as evident from an irreversible variation of the CuNCN redox behaviour in rotating ring-disc voltammetry. Furthermore, the accompanying structural and vibrational spectroscopy properties of the different MNCN compounds were explored with complementary ex situ analytical methods.
Azides and Cyanamides - Similar and Yet Different
Reckeweg, Olaf,Simon, Arndt
, p. 1097 - 1104 (2007/10/03)
The crystal structures of LiN3*;H2O (P6 3/mcm (No. 193), Z = 6; 924.01(13); 560.06(7) pm); NH 4N3 (Pmna (No. 53), Z = 4; a = 889.78(18), b = 380,67(8), c = 867.35(17) pm); Ca(N3)2 (Fddd (No. 70), Z = 8; a = 595.4(2), b = 1103.6(5), c = 1133.1(6) pm), Sr(N3)2 (Fddd(No. 70), Z = 8; a = 612.02(9), 6 = 1154.60(18), c = 1182.62(15) pm); Ba(N3)2 (P21/m (No. 11), Z = 2; a = 544.8(1), b = 439.9(1), c = 961.3(2) pm, β = 99.64(3)°) and TIN3 (I4/mcm (No. 140), Z = 2; 618.96(9); 732.71(15) pm) have been either determined for the first time or redetermined by X-ray diffraction on single crystals. The afore mentioned compounds, AN3 (A = Na, K, Rb, Cs), M(N 3)2 · 2.5 H2O (M = Mg, Zn) and the cyanamides Li2CN2, CdCN2 and CuCN2 were investigated by Raman and IR spectroscopy (KBr technique). Structural features and spectroscopic data of azides and cyanamides from this work and from literature are listed and compared.
