Rhenium and manganese carbonyl compounds incorporating tridentate chelating pyrazolyl gallate ligands

1985 ◽  
Vol 63 (8) ◽  
pp. 2261-2272 ◽  
Author(s):  
Brenda M. Louie ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter

The coordinating properties of a variety of unsymmetrical uninegative tridentate chelating "pyrazolylgallate" ligands have been studied using the tricarbonyl moieties "M(CO)3", where M = Mn or Re, as acceptor species. A series of monomeric, pseudo octahedral complexes has been characterized and a fac mode of coordination established for the tridentate gallate ligands from 1H nmr, ir measurements, and X-ray structure determinations. Nitrosylation of a selection of the rhenium tricarbonyl compounds has yielded a number of cationic rhenium mononitrosyl dicarbonyl species. The reactivity of these cations towards reducing agents has been investigated.

2020 ◽  
Vol 73 (6) ◽  
pp. 434
Author(s):  
Simon A. Cotton ◽  
Jack M. Harrowfield ◽  
Lioubov I. Semenova ◽  
Brian W. Skelton ◽  
Alexandre N. Sobolev ◽  
...  

X-Ray structure determinations on 41 complexes of lanthanide(iii) halides, principally bromides, with 2,2′-bipyridine, 1,10-phenanthroline, and 2,2′:6′,2″-terpyridine provide a considerable extension to the earlier work of Allan White on such materials and a substantial extension of general work on polypyridine complexes of lanthanide halides. Complexes of 1:1, 1:2, and 2:4 metal-to-ligand composition have been characterised across a broad selection of the lanthanide elements, many of these species showing a higher overall ratio of ligand to lanthanide due to the incorporation of uncoordinated ligand within the crystal lattice. Although stacking of the aromatic entities is apparent in these adducts, in most instances H-bonding of unbound N to coordinated water appears to be the principal interaction involved in their formation.


1988 ◽  
Vol 43 (7) ◽  
pp. 846-856 ◽  
Author(s):  
M. Veith ◽  
F. Goffing ◽  
V. Huch

Abstract The cis-isomer of the silazane H2L (1) (L = [NtBu][Me]Si(NtBu)2Si[Me][NtBu]) has been used as a ligand to main group metals. By displacing the hydrogen atoms of 1 the compounds L(MgMe)2 (4), L(MgCl)2 (5) and L(Li)(InMe2) (6) have been obtained. According to the 1H NMR spectra the structures of 4-6 are very similar: a polycyclic, cubane-like Si2N4M2 framework results from the special atomic arrangements and from intramolecular Lewis acid-base interactions between the metals M and the nitrogen atoms. Divalent metals and metal-centered groups can also be incorporated into 1. In the latter case a seco norcubane-like polycycle Si2N4M is produced as confirmed by X-ray structure determinations of LGaMe (8) and LSb+ InCl4- (11). LInMe (7) and LSn (9) seem to adopt the same tricyclic structure as 8, although the 1H NMR spectra are not consistent with a rigid molecule (low symmetry), but rather with a fluxional behaviour (high symmetry). When 5 is allowed to react with sodium/naphthalene in THF part of the magnesium is reduced and LMg(THF)2 (12) is formed. An X-ray structure determination of 12 reveals the compound to be only bicyclic with the magnesium atom coordinated by two nitrogen and two THF oxygen atoms.


1977 ◽  
Vol 10 (4) ◽  
pp. 389-392 ◽  
Author(s):  
D.F. Van de Vondel ◽  
L.F. Wuyts ◽  
G.P. Van der Kelen ◽  
L. Bevernage

1990 ◽  
Vol 45 (2) ◽  
pp. 221-238 ◽  
Author(s):  
Bernd Bachmann ◽  
Gerhard Baum ◽  
Jürgen Heck ◽  
Werner Massa ◽  
Bernd Ziegler

Synfacial binuclear μ-Cot complexes of the general formula X(Cp′M)2— μ-Cot with Cp′—X—Cp′ as an additional bridging group (M = V, Cr; Cot = cyclooctatetraene) can be prepared by a one-pot reaction of the appropriate metal dichlorides with K2Cot and Li2[(C5H4)2X]. For M = V the vanadocenophanes {V(Cp'2X)}2 (X = SiMe2, GeMe2) are isolated as by-products. Depending on the conditions of work-up for M = Cr µ-(σ:η3:η2-cyclooctatriene) complexes can be obtained instead of the μ-Cot compounds. X-ray structure determinations of several μ-Cot species attest only a poor influence of the bridging group X on the metal metal bond. Low temperature 1H NMR spectra of the dichromium μ-Cot complexes show that the rapid Cotrotation can be frozen below T = 200 K. Temperature dependent 1H NMR studies indicate a diamagnetic-paramagnetic equilibrium for the binuclear μ-C8H10 compounds, wherein a Cr,Crmultiple bond must be assumed.


1994 ◽  
Vol 49 (6) ◽  
pp. 788-800 ◽  
Author(s):  
Ralf Sonnenburg ◽  
Ion Neda ◽  
Axel Fischer ◽  
Peter G. Jones ◽  
Reinhard Schmutzler

The reaction of methylisatoic anhydride with 2-(aminomethyl)pyridine, 3-(aminomethyl)- pyridine, 3-dimethylamino-1-propylamine, 3-diethylamino-1-propylamine and 3-dibutylamino- 1-propylamine furnished the N-substituted N'-methylanthranilic amides 1-5. In the reaction of 1-5 with phosphorus trichloride the 3-substituted 5,6-benzo-1-m ethyl-1,3,2-diazaphosphorinane- 4-one derivatives 6 to 10 were obtained. The possibility of intramolecular donoracceptor interaction between the nitrogen atom of the R2N group and the λ3P atom is suggested on the basis of 1H NMR studies. The reaction of 9 with dimethylamino-trimethylsilane furnished the 2-dimethylamino-substituted product 11. In the reaction of 6, 7 and 10 with bis-(2-chloroethyl)amine hydrochloride/triethylamine the expected substitution products 12 to 14 were obtained. 5,6-Benzo-2-[bis-(2-chloroethyl)amino]-1-methyl-3-(3-picolyl)-1,3,2-diazaphosphorinan- 4-one 13 reacted with (COD)PtCl2 to give the czs-dichloro-platinum(II) complex 15. The characterisation of 1-15 is based on the 1H-, 13C-, and 31P-NMR spectra, mass spectra and X-ray structure determinations of the precursor compounds 1 and 3


2019 ◽  
Author(s):  
Swaraj Sengupta ◽  
Sahanwaj Khan ◽  
Shyamal K. Chattopadhyay ◽  
Indrani Banerjee ◽  
Tarun K. Panda ◽  
...  

Synthesis and characterisation of one trinuclear copper complex, ([Cu<sub>3</sub>L<sub>3</sub>O]ClO<sub>4</sub>) (<b>1</b>) and one nickel complex ([Ni(L'H)<sub>2</sub>(dmso)<sub>2</sub>](ClO<sub>4</sub>)<sub>2</sub>) (<b>2</b>) with Schiff base ligands: (3Z)-3-((Z)-(1-(thiophen-2-yl)ethylidene)hydrazono)butan-2-one oxime (LH) and 1-(pyridin-2-yl)ethylidene)hydrazono)butan-2-one oxime (L<sup>'</sup>H). <b>1</b> shows high catecholase activity and has also been tested as a catalyst for the synthesis of benzylimine. <b>2 </b> shows phenoxazinone synthase activity.


2018 ◽  
Vol 15 (2) ◽  
pp. 209-213 ◽  
Author(s):  
Sathish Mohan Botsa ◽  
Ramadevi Dharmasoth ◽  
Keloth Basavaiah

Background: During past two decades, functional nanomaterials have received great attention for many technological applications such as catalysis, energy, environment, medical and sensor due to their unique properties at nanoscale. However, copper oxide nanoparticles (NPs) such as CuO and Cu2O have most widely investigated for many potential applications due to their wide bandgap, high TC, high optical absorption and non-toxic in nature. The physical and chemical properties of CuO and Cu2O NPs are critically depending on their size, morphology and phase purity. Therefore, lots of efforts have been done to prepare phase CuO and Cu2O NPs with different morphology and size. Method: The synthesis of cupric oxide (CuO) and cuprous oxide (Cu2O) NPs using copper acetate as a precursor by varying the reducing agents such as hydrazine sulphate and hydrazine hydrate via sonochemical method. The phase, morphology and crystalline structure of a prepared CuO and Cu2O NPs were investigated by X-ray diffraction (XRD), Fourier transform infrared (FTIR), Field emission scanning electron microscopy (FESEM), Energy dispersive X-ray (EDS) and UV-Visible Diffuse reflectance spectroscopy (DRS). Results: The phase of NPs was tuned as a function of reducing agents.XRD patterns confirmed the formation of pure phase crystalline CuO and Cu2O NPs. FTIR peak at 621 cm-1 confirmed Cu(I)-O vibrations, while CuO vibrations confirmed by the presence of two peaks at 536 and 586 cm-1. Further investigation was done by Raman, which clearly indicates the presence of peaks at 290, 336, 302 cm-1 and 173, 241 cm-1 for CuO and Cu2O NPs, respectively. The FESEM images revealed rod-like morphology of the CuO NPs while octahedral like shape for Cu2O NPs. The presence of elemental Cu and O in stoichiometric ratios in EDS spectra confirms the formation of both CuO and Cu2O NPs. In summary, CuO and Cu2O NPs were successfully synthesized by a sonochemical method using copper acetate as a precursor at different reducing agents. The bandgap of CuO and Cu2O NPs was 2.38 and 1.82, respectively. Furthermore, the phase purity critically depends on reducing agents.


1981 ◽  
Vol 46 (10) ◽  
pp. 2345-2353 ◽  
Author(s):  
Karel Baše ◽  
Bohumil Štíbr ◽  
Jiří Dolanský ◽  
Josef Duben

The 6-N(CH3)3-6-CB9H11 carbaborane reacts with sodium in liquid ammonia with the formation of 6-CB9H12- which was used as a starting compound for preparing the 4-CB8H14, 9-L-6-CB9H13 (L = (CH3)2S, CH3CN and P(C6H5)3), 1-(η5-C5H5)-1,2-FeCB9H10-, and 2,3-(η5-C5H5)2-2,31-Co2CB9H10- carboranes. The 4-CB8H14 compound was dehydrogenated at 623 K to give 4-(7)-CB8H12 carborane. Base degradation of 6-N(CH3)3-6-CB9H11 in methanol resulted in the formation of 3,4-μ-N(CH3)3CH-B5H10. The structure of all compounds was proposed on the basis of their 11B and 1H NMR spectra and X-ray diffraction was used in the case of the transition metal complexes.


1995 ◽  
Vol 50 (7) ◽  
pp. 1018-1024 ◽  
Author(s):  
Axel Michalides ◽  
Dagmar Henschel ◽  
Armand Blaschette ◽  
Peter G. Jones

In a systematic search for supramolecular complexes involving all combinations of the cyclic polyethers 12-crown-4 (12C4), 15-crown-5 (15C 5), 18-crown-6 (18C 6) and dibenzo- 18-crown-6 (DB -18C6), and the geminal di- or trisulfones H2C(SO 2Me)2, H2C (SO2Et)2 and HC (SO2Me)3-n (SO2Et)n (n = 0 -3 ) , only the following four complexes could be isolated and unequivocally characterized by elemental analysis and 1H NMR spectroscopy: [(12C4){H2C (SO2Et)2}2] (3), [(18C6){H2C (S O2Me)2}] (4), [(DB -18C 6){H2C (SO2Et)2}] (5) and [(D B -18C 6)2{HC (SO2Me )(SO2Et)2}3] (6). The structure of 3 (triclinic, space group P1̄) consists of crystallographically centrosymmetric formula units, in which the disulfone molecules are bonded on each side of the ring by two C -H ··· O(crown) interactions originating from the central methylene group (H···O 213 pm) and from the methylene group of one EtSO2 moiety ( H ··· O 237 pm). Formula units related by translation are connected into parallel strands by a third type of reciprocal C -H ···O bond (H ···O 232 pm) between the second H atom of the central methylene group and a sulfonyl oxygen atom of the adjacent unit. The structure of 4 (monoclinic, space group C2/c) showed severe disorder of the crown ether and could not be refined satisfactorily. Compounds 5 and 6 crystallized as long and extremely thin fibres, indicative of linear-polymeric supramolecular structures; single crystals for X-ray crystallography were not available.


Sign in / Sign up

Export Citation Format

Share Document