A. Grodzicki

CVD of AgI complexes with tertiary phosphines and perfluorinated carboxylates : A new class of silver precursors

C 2 F 5 COOAgPMe 3 (1) and C 2 F 5 COOAg (2) have been used as precursors for the CVD of silver layers in the temperature range 493-623 K. The thin films obtained were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), scanning tunneling electrochemical microscopy (STEM), X-ray photoelectron spectroscopy (XPS), and temperature variable infrared (IR) measurements. The SEM images of Ag films grown from 2 exhibited a surface with a grain size in the range 0.4-1.5 μm, whereas from 1 the size was ∼0.1 μm. This was confirmed by the STEM studies. The better stability of 1 in the vapor phase was proved by temperature variable IR spectra (373-523 K). Mass spectrometry (MS) images confirmed the presence of the monomeric and dimeric species, and the recombination ions transported in vapors. The XPS image analysis of the silver layers revealed the presence of some carbon impurities. The films demonstrated good adhesion to silicon substrates.

Heteronuclear multiple-quantum correlation 15N–1H, cross-polarized magic angle spinning 13C, 15N nuclear magnetic resonance and infrared spectroscopic studies of 1,2,4-triazolo-[1,5α]-pyrimidine and its Zn(II) halide and thiocyanate complexes

Abstract 1,2,4-Triazolo-[1,5α]-pyrimidine (tp) was studied by gradient heteronuclear multiple-quantum correlation 15N–1H NMR and by cross-polarized magic angle spinning 13C, 15N NMR. The 15N signals were unambiguously assigned. The assignments of some IR absorption bands were proposed by comparison to purine and adenine spectra. The obtained results were used for the investigation of Zn(tp)2X2-type complexes (X=Cl, Br, I, NCS), suggesting a pseudo-tetrahedral configuration around the Zn(II) ion with unidentately N(3) bonded heterocycles and halides or thiocyanates (N bonded) in terminal positions. A slight shielding effect on the N(3) nucleus upon the formation of Zn(II)–N coordination bonding was observed.

The molecular structures of copper(II) chloroacetate complexes with5,7-dimethyl-1,2,4-triazolo-[1,5-α]-pyrimidine and 5,7-diphenyl-1,2,4-triazolo-[1,5-α]-pyrimidine

Abstract Copper(II) complexes of formula Cu2(CH2ClCOO)4(dmtp)2 (1) and Cu2(CN2ClCOO)4(dptp)2 (2), wheredmtp=5,7-dimethyl-1,2,4-triazolo-[1,5-α]-pyrimidine anddptp=5,7-diphenyl-1,2,4-triazolo-[1,5-α]-pyrimidine, were obtained. The X-ray diffraction analysis of 1 exhibited the dimeric structure with chloroacetate bridges. The coordination sphere of Cu(II) ion is a slightly distorted square pyramid, with 4 equatorial carboxylic oxygens and anaxially N(3) bonded dmtp molecule. The distance Cu–Cu is 2.7035(7) Aand the distance between Cu and O4 plane is 0.239(1) A(towards the axial ligand). The distances Cu–O are 1.954(2)–1.981(2) A,Cu–N 2.150(1) A. The angles O–Cu–O are 87.88(8)–90.56(8)° and166.04(6)–166.07(5)°, O–Cu–N 90.08(7)–103.76(7)°. The O4 plane is not perpendicular to the Cu · · · Cu line, the angles O–Cu–Cu being 82.04(5)–84.00(5)° and N–Cu–Cu169.54(4)°. Spectroscopic (IR, UV, EPR) and magnetic studies suggested that 2 has the analogous structure to 1.

Thermal and spectroscopic studies of the Ag(I) salts with fluorinated carboxylic and sulfonic acid residues

Abstract Silver(I) salts with RCOOH, where R is CF 3 CF 2 ) 2 , CF 3 (CF 2 ) 6 , CF 3 (CF 2 ) 8 C 6 F 5 , C 6 F 5 CH 2 , with RSO 3 H, where R is CF 3 , CF 3 (CF 2 ) 3 , and with HOOC(CF 2 ) 3 COOH were synthesized. The thermal decomposition processes were studied and the activation energies calculated from thermal data. The decomposition mechanisms and thermal stabilities are discussed. From the IR, and 13 C and 19 F NMR measurements, it is proposed that the carboxylic acid residues have monodentate bonding.

Thermal studies of Ag(I) complexes with triethylphosphine and perfluorinated carboxylates

Abstract Silver(I) complexes with triethylphosphine and perfluorinated carboxylic acids residues of general formula [Et 3 PAgOOCR] 2 , where R=C 2 F 5 , C 3 F 7 , C 6 F 13 , C 7 F 15 , C 8 F 17 , C 9 F 19 , C 6 F 5 and Et 3 PAgOOC(CF 2 ) 3 COOAgPEt 3 , were synthesized. Thermal decomposition proceeded in two stages – both exothermic processes corresponding to the elimination of carboxylate and triethylphosphine residues. The final product of the thermal decomposition was metallic silver. Analyses by 13 C, 19 F, 31 P NMR spectroscopy and vibrational spectra suggest trigonal coordination of Ag(I), the coordination sphere consisting of unidentate triethylphosphine and bidentate carboxylates forming bridges between metal ions.

Thermal and spectroscopic studies of Ag(I) complexes with trimethylphosphine and perfluorinated carboxylates

Abstract Silver(I) complexes with trimethylphosphine and perfluorinated carboxylates of the general formula [Me 3 PAgOOCR] 2 , where R  C 2 F 5 , C 3 F 7 , C 6 F 13 , C 7 F 15 , C 8 F 17 , C 9 F 19 , C 6 F 5 and Me 3 PAgOOC(CF 2 ) 3 have been prepared and their thermal decomposition studied. Thermal decomposition proceeded in multistages, starting with the detachment of carboxylates and followed by trimethylphosphine dissociation. The final product was metallic silver. The temperatures of silver formation were in the 473–633 K range. Complexes were characterised by 13 C, 19 F, 31 P NMR and vibrational spectra. Spectral analysis favoured Ag(I) trigonal coordination with unidentate trimethylphosphine and bidentate carboxylates forming bridges between silver(I) ions.

A copper(II) chloride complex of hexamethylenetetramine

SummaryThe 3CuCl2·4hmta·2HCl·2H2O complex (hmta=hexamethylenetetramine) has been obtained from acid solution. Spectroscopic and magnetic investigations indicate that, in the crystal structure of this compound, the polymeric chains, 3CuCl2·2hmta·2H2O, and hmta·HCl groups occur.

Magnetostructural characterisation of the first bimetallic assemblies derived from the anionic building block [Cr(NCS)6]3− [M(en)3]n[{M(en)2-μ-SCN-Cr(NCS)4-μ-NCS}2n] with M = Ni(II), Zn(II)

Two bimetallic complexes [M(en)3]n[{M(en)2Cr(NCS)6}2n] (M = Ni 1, Zn 2; en = ethylenediamine) have been prepared and structurally and magnetically characterised. They present a unique structure consisting of two distinct units: the catena-μ-NCS-M(en)2-μ-SCN-Cr(NCS)4 1-D polymeric anion and the monomeric cations [M(en)3]2+. Complex 1 crystallized in the monoclinic system, space group C2/c, with a = 28.330(3), b = 14.256(1), c = 16.013(1) A, β = 117.26(1)°, V = 5748.9(8) A3 and Z = 4. The crystal structure of 1 has been refined to R1 = 0.0808. The bridging NCS ligands occupy the rare cis positions in the Ni2+ coordination sphere and are coordinated to nickel via their sulfur atoms. The coordination sphere of Cr3+ is formed by six nitrogen atoms of the NCS ligands. The Ni–N distances vary from 2.052(5) to 2.131(5) A, the Ni–S distances are 2.584(2) and 2.632(2) A, whereas the Cr–N distances vary from 1.971(6) to 2.003(6) A. A variable temperature magnetic susceptibility study of 1 has been performed over the temperature range of 4–300 K. The compound shows antiferromagnetic coupling (J ≈ −20 cm−1). This moderate antiferromagnetic interaction could be explained by the structural features related to μ-N,S-NCS bridged units being in cis positions at both metallic centres. The isostructural complex 2 exhibits magnetic behaviour that agrees well with that expected for isolated [Cr(NCS)6]3− units with small inter- and/or intra-chain antiferromagnetic interactions.