Nitrosyl complexes of rhenium. 3. The synthesis and substitution reactions of [ReH(CH3OH)(NO)(PPh3)3]ClO4 derived from the reaction of ReH2(NO)(PPh3)3 with HClO4. Members of the series ReHX(NO)(PPh3)3

1989 ◽  
Vol 67 (7) ◽  
pp. 1187-1192 ◽  
Author(s):  
Julie Y. Chen ◽  
Kevin R. Grundy ◽  
Katherine N. Robertson
Keyword(s):  
Infrared Spectroscopy ◽  
Solid State ◽  
Nmr Spectroscopy ◽  
Ambient Conditions ◽  
Substitution Reactions ◽  
Rhenium Complexes ◽  
Counter Ion ◽  
Elemental Analyses ◽  
Neutral Ligands ◽  
Hydrogen Bound

ReH2(NO)(PPh3)3 reacts with alcoholic HClO4 to yield the solvated cation, [ReH(ROH)(NO)(PPh3)3]ClO4 (R = CH3, C2H5) which can be isolated as an explosive solid (R = CH3 only). In the solid state, the perchlorate counter ion is hydrogen bound to the ligated alcohol, as observed for [ReH(CH3OH)(CO)(NO)(PPh3)2]ClO4. This latter complex also results from the reaction of [ReH(CH3OH)(NO)(PPh3)3]ClO4 with CO under ambient conditions. On reaction with p-tolylisocyanide (RNC), however, substitution is also accompanied by dihydrogen elimination to give [Re(OR)(NO)(CNR)2(PPh3)2]ClO4, irrespective of the mole ratio of the reactants. In contrast, [ReH(CH3OH)(NO)(PPh3)3]ClO4 reacts with coordinating anions with loss of methanol to give air-sensitive ReHX(NO)(PPh3)3 (X = OCH3, F, Cl, Br, I, N3, NCO, SCN), of which only those with X = Cl, Br, N3 were characterized in solution. The compounds ReHX(NO)(PPh3)3 are similar to their osmium analogues in having a labile third phosphine. Thus, reaction with neutral ligands such as CO or RNC leads to the series of neutral rhenium hydrido nitrosyls ReHX(L)(NO)(PPh3)2. Prior to this work, the only known examples from this series were those with L = CO, X = H, F, OCH3. Interestingly, the isomer of ReHF(CO)(NO)(PPh3)2 isolated in this work differs from that previously isolated (from the reaction of [ReF(CO)(NO)(PPh3)3]+ with [Formula: see text]) in having F trans to NO. All structural assignments have been made on the basis of elemental analyses, infrared spectroscopy, 1H and 31P nmr spectroscopy and deuteration studies, where appropriate. Keywords: hydrido, nytrosyl, rhenium, complexes.

Reactions of 7-azaindole with niobium and tantalum pentachlorides and coupling to the azaindolyl-azaindolium cation

1994 ◽  
Vol 72 (7) ◽  
pp. 1675-1683 ◽  
Author(s):  
Jacques Poitras ◽  
André L. Beauchamp
Keyword(s):  
Infrared Spectroscopy ◽  
Nmr Spectroscopy ◽  
Crystal Structures ◽  
Infrared Spectra ◽  
Oxidative Coupling ◽  
Room Temperature ◽  
H Nmr ◽  
Counter Ion ◽  
Distorted Octahedral ◽  
Complex Salts

The reaction of NbCl5 and TaCl5 with 7-azaindole (Haza) at room temperature in benzene or dichloromethane yielded MCl5(Haza) addition compounds. Under more severe conditions, the same compound was obtained with TaCl5. For NbCl5, some reduction to Nb(IV) was observed and NbCl5(Haza), NbCl4(Haza)2, and the (H2aza)+ ion were identified in the reaction mixture by infrared spectroscopy. Oxidative coupling of two azaindole units via N7—C6 also took place during the reaction, since the 7-(azaindol-6-yl)azaindolium cation was found as counter-ion in the crystal structures of two complex salts. In the crystals of (H2aza-aza)[NbOCl4(Haza)]•0.5CH2Cl2([Formula: see text]a = 7.255 Å, b = 12.412 Å, c = 14.277 Å, α = 89.03°, β = 85.60°, γ = 76.66°, Z = 2, R = 0.062), the anion is the roughly octahedral [NbOCl4(azaindole)]− species containing a neutral N7-coordinated azaindole trans to the Nb=O bond. The [NbOCl5]2− salt ([Formula: see text]a = 7.527 Å, b = 10.168 Å, c = 10.467 Å, α = 66.41°, β = 84.07°, γ = 85.51°, Z = 1, R = 0.037) contains the distorted octahedral [NbOCl5]2− ion disordered over two orientations. The infrared spectra suggest monomeric octahedral structures for the MCl5(Haza) and NbCl4(Haza)2 complexes. 1H NMR spectroscopy shows that NbCl5(Haza) is not dissociated in CD2Cl2.

Synthesis, Characterization, and Crystal Structures of [Cu(ca2en)(PPh3)(X)] (X = Cl, Br, I, NCS, N3) Complexes

2003 ◽  
Vol 56 (4) ◽  
pp. 323 ◽  
Author(s):  
Guido Kickelbick ◽  
Mehdi Amirnasr ◽  
Aliakbar D. Khalaji ◽  
Saeed Dehghanpour
Keyword(s):  
Infrared Spectroscopy ◽  
Nmr Spectroscopy ◽  
31P Nmr ◽  
Mixed Ligand ◽  
Bond Breaking ◽  
31P Nmr Spectroscopy ◽  
Distorted Tetrahedron ◽  
Nmr Studies ◽  
X Ray ◽  
Elemental Analyses

Novel mixed-ligand copper(I) complexes, [Cu(ca2en)(PPh3)X] (ca2en = N,N′-bis(trans-cinnamaldehyde)-1,2-diaminoethane, X = Cl (1), Br (2), I (3), NCS (4), N3 (5)), have been synthesized and characterized by 1H and 31P NMR spectroscopy, infrared spectroscopy, and elemental analyses. The single crystal X-ray structures of complexes (1)–(5) have been determined. All five complexes reveal discrete monomeric structures in the crystal. The geometry around the copper atom is in each case a distorted tetrahedron, with the distortion most pronounced in (3). The NCS− and N3− are coordinated as terminal ligands and the NCS− ligand is N-bonded in (4). Dynamic 31P NMR studies show partial bond breaking in solution.

Spectroscopic characterization of silica aerogels prepared using several precursors – effect on the formation of molecular clusters

2017 ◽  
Vol 41 (14) ◽  
pp. 6742-6759 ◽  
Author(s):  
A. Borba ◽  
J. P. Vareda ◽  
L. Durães ◽  
A. Portugal ◽  
P. N. Simões
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Solid State ◽  
Nmr Spectroscopy ◽  
Solid State Nmr ◽  
Spectroscopic Characterization ◽  
Spectroscopic Properties ◽  
Silica Aerogels ◽  
Molecular Clusters

The structural and spectroscopic properties of silica aerogels were studied using complementary approaches, such as Fourier transform infrared spectroscopy and solid-state NMR spectroscopy.

Synthese und Eigenschaften von Rhenium-Komplexen mit N2-, N2H2-, N2H4- und NH3-Liganden / Synthesis and Properties of Rhenium Complexes with N2, N2H2, N2H4 and NH3 Ligands

1977 ◽  
Vol 32 (7) ◽  
pp. 795-801 ◽  
Author(s):  
D. Sellmann ◽  
E. Kleinschmidt
Keyword(s):  
Uv Irradiation ◽  
Room Temperature ◽  
Manganese Complex ◽  
Ambient Conditions ◽  
Rhenium Complexes ◽  
Nitrogen Ligands ◽  
Rhenium Complex ◽  
Elemental Analyses ◽  
First Time

UV irradiation of C5H5Re(CO)3 in tetrahydrofuran (THF) yields the THF complex C5H5Re(CO)2THF and traces of [(C5H5)2Re2(CO)5]. C5H5Re(CO)2THF is stable at room temperature, its reaction with N2/100 bar yields C5H5Re(CO)2N2, which also forms in the reaction with N2O whereby the THF complex is partially oxidized and decomposed. The reaction with an excess of N2H4 yields C5H5Re(CO)2N2H4, the oxidation of which leads to C5H5Re(CO)2N2 and the by-product trans-N2H2[C5H5Re(CO)2]2, in which the under ambient conditions unstable HN=NH molecule could be stabilized in a rhenium complex for the first time. In contrast to the analogous manganese complex C5H5Re(CO)2N2H4 disproportionates easily to C5H5Re(CO)2N2 and C5H5Re(CO)2NH3 at room temperature; the NH3 complex can be synthesized directly only by irradiating C5H5Re(CO)3 in hexane in the presence of NH3. The complexes are characterized spectroscopically and by elemental analyses; the different electronic influence of the nitrogen ligands on the C5H5Re(CO)2 system is discussed.

IR and 13C, 17O, and 119Sn NMR spectra of some bis(1-butyl)tin(IV) carboxylates of dicarboxylic acids

1991 ◽  
Vol 56 (9) ◽  
pp. 1908-1915 ◽  
Author(s):  
Jaroslav Holeček ◽  
Antonín Lyčka ◽  
Milan Nádvorník ◽  
Karel Handlíř
Keyword(s):  
Infrared Spectroscopy ◽  
Nmr Spectroscopy ◽  
Dicarboxylic Acid ◽  
Nmr Spectra ◽  
Dicarboxylic Acids ◽  
119Sn Nmr ◽  
Carboxylic Groups ◽  
Cyclic Oligomers ◽  
The Media ◽  
Oxygen Atoms

Infrared spectroscopy and multinuclear (13C, 17O, and 119Sn NMR spectroscopy have been used to study the structure of bis(1-butyl)tin(IV) carboxylates of dicarboxylic acids (1-C4H9)2. Sn(X(COO)2), where X = (CH2)n (n = 0-8), CH=CH (cis and trans) and C6H4 (ortho and para).The crystalline compounds are formed by linear or cyclic oligomers or polymers whose basic building units represent a grouping composed of the central tin atom substituted by two 1-butyl groups and coordinated with both oxygen atoms of two anisobidentate carboxylic groups derived from different molecules of a dicarboxylic acid. The environment of the tin atom has a shape of a trapezoidal bipyramid. When dissolvet in non-coordinating solvents, the compounds retain the oligomeric character with unchanged structure of environment of the central tin atom. In the media of coordinating solvents the bis(1-butyl)tin(IV) carboxylates of dicarboxylic acids form complexes whose central hexacoordinated tin atom binds two molecules of the solvent trough their donor atoms. Carboxylic groups form monodenate linkages in these complexes.

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