1,4,8,11-Tetra[2-aryl-1-diazenyl]-1,4,8,11-tetraazacyclotetradecanes — Synthesis, characterization, and X-ray crystallography of the first tetrakistriazenes to be reported

2006 ◽  
Vol 84 (10) ◽  
pp. 1280-1289 ◽  
Author(s):  
Jeffery D Clarke ◽  
Keith Vaughan ◽  
Valerio Bertolasi
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Electrospray Mass Spectrometry ◽  
Diazonium Salt ◽  
Diazonium Salts ◽  
The Novel ◽  
Analogous Reaction ◽  
X Ray ◽  
X Ray Crystallography ◽  
The Mean

The reactions of a series of arene diazonium salts with 1,4,8,11-tetraazacyclotetradecane (cyclam) afford the novel compounds, the 1,4,8,11-tetra[2-aryl-1-diazenyl]-1,4,8,11-tetraazacyclotetradecanes (1a–1f), which are the first examples of tetrakistriazenes to be reported. The tetrakistriazenes were characterized by IR spectroscopy, proton and carbon NMR, elemental analysis, high resolution electrospray mass spectrometry, and X-ray crystallography. The analogous reaction of a diazonium salt with 1,4,7-triazacyclononane or 1,5,9-triazacyclododecane yields the tristriazenes 2, 3a, and 3b. The structures of compounds 1c and 1e were solved by X-ray crystallography at low temperature (150 K). Both molecules display a conformation where the four phenyltriazenyl groups point alternately upwards and downwards with respect to the mean macrocyclic plane.Key words: triazene, tetrakistriazene, cyclam, tetraazacyclotetradecane, X-ray, NMR, cyclic polyamines.

Triazene derivatives of (1,x)-diazacycloalkanes. Part VII. Synthesis of a series of 1-aryl-2-[3-(3-[2-aryl-1-diazenyl]-1,3-diazepan-1-ylmethyl)-1,3-diazepan-1-yl]-1-diazenes from the reaction of diazonium salts with mixtures of formaldehyde and 1,4-diaminobutane

2006 ◽  
Vol 84 (10) ◽  
pp. 1434-1441
Author(s):  
Reid Tingley ◽  
Keith Vaughan
Keyword(s):  
Diazonium Salt ◽  
Diazonium Salts ◽  
The Novel ◽  
Cage Structure ◽  
X Ray Crystallography ◽  
New Compounds ◽  
Type 3 ◽  
Bicyclic Molecules

A new series of bistriazenes, the 1-aryl-2-[3-(3-[2-aryl-1-diazenyl]-1,3-diazepan-1-ylmethyl)-1,3-diazepan-1-yl]-1-diazenes (8), has been synthesized from the reaction of diazonium salts with a mixture of 1,4-diaminobutane and formaldehyde. All new compounds of series 8 have been characterized by IR and NMR spectroscopy, and the elemental composition of selected examples has been verified by elemental analysis. The connectivity of the series has been unequivocally determined by X-ray crystallography. The new bistriazenes are important because the structure contains the novel saturated heterocycle, 1,3-diazepane. The general conclusion of this study is that alkanediamines with three or four carbon atoms in the spacer link between the nitrogen atoms give rise to the linear bicyclic molecules of type 2, in contrast to the case of ethylenediamine (two carbon atoms in spacer link), which affords molecules of type 3, which exemplify the cage structure of type 1.Key words: diazonium salt, triazene, bistriazene, diazepane, formaldehyde, nuclear magnetic resonance.

scholarly journals Contaminant inclusion into protein crystals analyzed by electrospray mass spectrometry and X-ray crystallography

1998 ◽  
Vol 7 (1) ◽  
pp. 185-192 ◽  
Author(s):  
Juan Carlos Fontecilla-Camps ◽  
Frédéric Halgand ◽  
Eric Forest ◽  
Joachim Hirschler
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Mass Spectrometry ◽  
Protein Crystals ◽  
X Ray ◽  
X Ray Crystallography

Protein interactions of dirhodium tetraacetate: a structural study

2020 ◽  
Vol 49 (8) ◽  
pp. 2412-2416 ◽  
Author(s):  
Giarita Ferraro ◽  
Alessandro Pratesi ◽  
Luigi Messori ◽  
Antonello Merlino
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Protein Interactions ◽  
High Resolution Mass Spectrometry ◽  
Rnase A ◽  
Pancreatic Ribonuclease ◽  
X Ray ◽  
X Ray Crystallography ◽  
Model Protein ◽  
Resolution Mass

The interactions between the cytotoxic paddlewheel dirhodium complex [Rh2(μ-O2CCH3)4] and the model protein bovine pancreatic ribonuclease (RNase A) were investigated by high-resolution mass spectrometry and X-ray crystallography.

Tracking the dissolution–recrystallization structural transformation (DRST) of copper(II) complexes: a combined crystallographic, mass spectrometric and DFT study

2020 ◽  
Vol 76 (7) ◽  
pp. 655-662
Author(s):  
Qian-Jun Deng ◽  
Min Chen ◽  
Dong-Chu Chen ◽  
Hang-Yu Long ◽  
Chang-Ai Chen
Keyword(s):  
Mass Spectrometry ◽  
Structural Transformation ◽  
Density Functional ◽  
Electrospray Mass Spectrometry ◽  
Theoretical Calculations ◽  
Binuclear Copper ◽  
Functional Theory ◽  
X Ray ◽  
X Ray Crystallography ◽  
First Time

Methanol- and temperature-induced dissolution–recrystallization structural transformation (DRST) was observed among two novel CuII complexes. This is first time that the combination of X-ray crystallography, mass spectrometry and density functional theory (DFT) theoretical calculations has been used to describe the fragmentation and recombination of a mononuclear CuII complex at 60 °C in methanol to obtain a binuclear copper(II) complex. Combining time-dependent high-resolution electrospray mass spectrometry, we propose a possible mechanism for the conversion of bis(8-methoxyquinoline-κ2 N,O)bis(thiocyanato-κN)copper(II), [Cu(NCS)2(C10H9NO)2], Cu1, to di-μ-methanolato-κ4 O:O-bis[(8-methoxyquinoline-κ2 N,O)(thiocyanato-κN)copper(II)], [Cu2(CH3O)2(NCS)2(C10H9NO)2], Cu2, viz. [Cu(SCN)2(L)2] (Cu1) → [Cu(L)2] → [Cu(L)]/L → [Cu2(CH3O)2(NCS)2(L)2] (Cu2). We screened the antitumour activities of L (8-methoxyquinoline), Cu1 and Cu2 and found that the antiproliferative effect of Cu2 on some tumour cells was much greater than that of L and Cu1.

Organozinc Siloxide-Hydrazide Aggregates [(RZn)4(NHNMe2)x(OSiMe3)(4 – x)]

2006 ◽  
Vol 61 (7) ◽  
pp. 838-845 ◽  
Author(s):  
Surajit Jana ◽  
Roland Fröhlich ◽  
Norbert W. Mitzel
Keyword(s):  
Mass Spectrometry ◽  
Ir Spectroscopy ◽  
General Formula ◽  
Elemental Analysis ◽  
Mirror Symmetry ◽  
The Novel ◽  
X Ray ◽  
X Ray Crystallography ◽  
The Core ◽  
Mixed Aggregates

The reaction of dialkylzinc compounds R2Zn (R = Me, Et) with N,N-dimethylhydrazine and trimethylsilanol in a 4 : 2 : 2 ratio leads to the formation of tetra(alkylzinc) tris-siloxide monohydrazide aggregates, [(RZn)4(NHNMe2)(OSiMe3)3] [R = Me (1) and Et (2)]. These compounds are aggregates of mirror symmetry, containing the novel Zn4N2O3 core. Both compounds have been characterised by 1H, 13C and 29Si NMR and IR spectroscopy, by mass spectrometry and by elemental analysis, and 2 also by X-ray crystallography. The structure can be derived from a heterocubane, in which one anionic vertex is replaced by an NHNMe2 group contributing two N atoms to the core constitution. By applying a ratio of hydrazine : silanol of 2 : 1 in a reaction with R2Zn (R = Me, Et, iPr), compounds of the general formula [(RZn)4(NHNMe2)2(OSiMe3)2] [R = Me (3), Et (4), iPr (5)] are obtained. These aggregates contain a Zn4N4O2 core. Upon employing a hydrazine : silanol ratio of 5 : 1 in a reaction with diisopropyl zinc, the compound [(iPrZn)4(NHNMe2)3(OSiMe3)] results, containing a Zn4N6O unit. Compounds 3 - 6 have been characterised by 1H, 13C and 29Si NMR and IR spectroscopy, by mass spectrometry and by elemental analysis. The topologic relationship between the pure hydrazides [(RZn)4(NHNMe2)4], the mixed aggregates [(RZn)4(NHNMe2)3(OR’)], [(RZn)4(NHNMe2)2(OR’)2] and [(RZn)4(NHNMe2)3(OR’)3] and the pure alkoxides [(RZn)4(OR’)4] is discussed.

Reaktion von Oxomolybdän-Komplexen mit Alkyldithiocarbazaten. Darstellung und Charakterisierung von Hydrazido- und Diazenido-Komplexen des Molybdäns / Reaction of Oxomolybdenum Complexes with Alkyldithiocarbazates. Synthesis and Characterization of Hydrazido- and Diazenido Complexes of Molybdenum

1987 ◽  
Vol 42 (5) ◽  
pp. 589-598 ◽  
Author(s):  
Rainer Mattes ◽  
Heinz Scholand ◽  
Ulrich Mikloweit ◽  
Volker Schrenk
Keyword(s):  
Tridentate Ligand ◽  
The Novel ◽  
Unique Combination ◽  
Dimeric Complex ◽  
X Ray ◽  
X Ray Crystallography ◽  
Metal Atoms ◽  
The Mean ◽  
Trigonal Prismatic

(2).The reaction of alkyldithiocarbazates NH2NHC(S)SR′ with MoO2(S2CNR2)2 R, R′ = Me, Et) yields the diazenido hydrazido complexes Mo(NNC(S)SR′)(NH2NC(S)SR′)(S2CNR2)2 (1), reaction with the molybdenum hydroxylamidate complex MoO2(ONMe2)2 gives the diazenidobis( hydrazido) complex Mo(NNC(S)SMe)(NH2NC(S)SMe)2(Me2NO)-CH3OH The crystal structures of 1 a (R = Me, R′ = Et) and 2 have been determined. The metal atoms in 1 a and 2 are seven coordinated and have MoN2S5 and MoN3O2S2 ligand arrays, respectively. Both compounds contain the approximately linear diazenido ligand NNC(S)SR in addition to one (1a) or two (2) N,S-chelating hydrazido(1-) ligands NH2NC(S)SR. When 1a is treated with HCl, the dimeric complex (Me2NCS2)(O)Mo(μ-NNC(S)SEt)2 Mo(S2CNMe2) (4) is obtained. X-ray crystallography showed 4 to be an asymmetric dinuclear complex, with a Mo-Mo distance of 267.2(1) pm. One Mo site has a square pyramidal MoOS2N2 geometry, while the other one has an approximately trigonal prismatic MoN2S4 geometry. The mean N-N distance in 4 is 135(1) pm. The reaction of NH2NHC(S)SMe with MoO2(acac)2 yields Mo(Me2CNNC(S)SMe)(NNC(S)SMe)(MeSC(S)NNC(S)SMe) (3). Its structure has been determined by X-ray crystallography. 3 contains a unique combination of three different N- and S-chelating ligands: the Schiff base Me2C=NNC(S)SMe, the highly bent bidentate diazenido ligand NNC(S)SMe (∡ Mo-N-N = 142.1(5)°), and the novel planar tridentate ligand MeSC(S)NNC(S)SMe. The latter can be taken as neutral diacyldiazene or, more likely, as the dianion of the as yet unknown MeSC(S)NH -NHC(S)SMe. The N - N distance in this ligand is 136.1(9) pm.

scholarly journals A case of extensive protein platination: the reaction of lysozyme with a Pt(ii)–terpyridine complex

2018 ◽  
Vol 47 (26) ◽  
pp. 8716-8723 ◽  
Author(s):  
Giarita Ferraro ◽  
Tiziano Marzo ◽  
Teresa Infrasca ◽  
Agostino Cilibrizzi ◽  
Ramon Vilar ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Mass Spectrometry ◽  
High Reactivity ◽  
Experimental Conditions ◽  
X Ray ◽  
X Ray Crystallography ◽  
Cytotoxic Compound ◽  
Model Protein

The interaction between a Pt(ii)–terpyridine cytotoxic compound and the model protein lysozyme has been investigated by X-ray crystallography and electrospray mass spectrometry under different experimental conditions. The compound shows a high reactivity with the model protein.

Electron microscopy of rabbit FC crystals

1983 ◽  
Vol 41 ◽  
pp. 730-731
Author(s):  
Robert A. Grant ◽  
Laura L. Degn ◽  
Wah Chiu ◽  
John Robinson
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Molecular Replacement ◽  
X Ray ◽  
X Ray Crystallography ◽  
Resolution Electron ◽  
Replacement Technique ◽  
Hydrated Crystal ◽  
Molecular Structure Analysis

Proteolytic digestion of the immunoglobulin IgG with papain cleaves the molecule into an antigen binding fragment, Fab, and a compliment binding fragment, Fc. Structures of intact immunoglobulin, Fab and Fc from various sources have been solved by X-ray crystallography. Rabbit Fc can be crystallized as thin platelets suitable for high resolution electron microscopy. The structure of rabbit Fc can be expected to be similar to the known structure of human Fc, making it an ideal specimen for comparing the X-ray and electron crystallographic techniques and for the application of the molecular replacement technique to electron crystallography. Thin protein crystals embedded in ice diffract to high resolution. A low resolution image of a frozen, hydrated crystal can be expected to have a better contrast than a glucose embedded crystal due to the larger density difference between protein and ice compared to protein and glucose. For these reasons we are using an ice embedding technique to prepare the rabbit Fc crystals for molecular structure analysis by electron microscopy.

scholarly journals 4-vinylpyridine derivatives: Protonation, methylation and silver(I) coordination chemistry

2021 ◽  
pp. 174751982198965
Author(s):  
Guoqi Zhang
Keyword(s):  
Mass Spectrometry ◽  
Schiff Base ◽  
Coordination Chemistry ◽  
Elemental Analysis ◽  
Silver Complex ◽  
Spectroscopic Techniques ◽  
X Ray ◽  
X Ray Crystallography ◽  
Pyridine Moiety ◽  
New Compounds

( E)-4-[2-(Pyridin-4-yl)vinyl]benzaldehyde, containing both a 4-vinylpyridine and an aldehyde functionality, is utilized to develop new, highly conjugated chalcone compounds and a bis-Schiff base azine compound. The chalcone-containing compounds are further explored for their protonation, methylation and silver(I) coordination chemistry using the pyridine moiety. In parallel, a cyano-containing analogue, ( E)-4-[2-(pyridin-4-yl)vinyl]benzonitrile is also synthesized and studied for its silver(I) coordination chemistry. These new compounds are fully characterized by mass spectrometry, elemental analysis and spectroscopic techniques. The methylated product of ( E)-1-(9-anthryl)-3-{4-[2-(pyridin-4-yl)vinyl]phenyl}prop-2-en-1-one and a silver complex of ( E)-4-[2-(pyridin-4-yl)vinyl]benzonitrile are structurally determined by X-ray crystallography.

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