Calixcrown Binding to Alkali Metal Cations—Comparison of Two 1,3-Alternate Calix[4]arenebiscrown-5 Ligands

1996 ◽  
Vol 49 (2) ◽  
pp. 183 ◽  
Author(s):  
R Abidi ◽  
Z Asfari ◽  
JM Harrowfield ◽  
AN Sobolev ◽  
J Vicens
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Alkali Metal ◽  
Chloroform Solution ◽  
Metal Cations ◽  
Alkali Metal Cations ◽  
Triclinic Space Group ◽  
Space Group ◽  
Solid State Conformation

While determination of the crystal structure of 1,3;2,4-biscrown-5-calix[4] arene (chloroform solvate, triclinic. space group Pī, a 11.151(4), b 16.832(6), c 21.929(8) Ǻ, α 98.78(3), β 92.02(3), γ 92.12(3)°, Z = 4 f.u ., conventional R on |F| 0.085 for 4699 'observed', I > 2σ(I), reflections) shows that this ligand has a closely similar solid state conformation to that of its previously characterized, substituted analogue, 1,3;2,4-biscrown-5-p-t-butylcalix[4] arene, the two ligands do differ significantly in their interactions with alkali metal picrates in chloroform solution. Most obviously, the t-butyl substituents of the latter ligand appear to inhibit caesium binding. changing the nature of the interactions to a form similar to that of both ligands with Li+ and Na+, for which 1H n.m.r. spectroscopy indicates weak exocyclic binding to some of the polyether oxygen atoms. 1H n.m.r. spectroscopy also provides evidence of picrate binding to the metals in isomeric forms.

Influence of Alkali Metal Cations on the Photodimerization of Bromo Cinnamates Studied by Solid-State NMR

2020 ◽  
Vol 124 (50) ◽  
pp. 27614-27620
Author(s):  
Marufa Zahan ◽  
He Sun ◽  
Sophia E. Hayes ◽  
Harald Krautscheid ◽  
Jürgen Haase ◽  
...  
Keyword(s):  
Solid State ◽  
Alkali Metal ◽  
Solid State Nmr ◽  
Metal Cations ◽  
Alkali Metal Cations

Mass Spectrometric Behaviour of Carboxylated Polyethylene Glycols and Carboxylated Octylphenol Ethoxylates

2003 ◽  
Vol 9 (3) ◽  
pp. 165-173 ◽  
Author(s):  
Magdalena Frańska ◽  
Agnieszka Zgoła ◽  
Joanna Rychłowska ◽  
Andrzej Szymański ◽  
Zenon Łukaszewski ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Alkali Metal ◽  
Mass Spectra ◽  
Secondary Ion Mass Spectrometry ◽  
Metal Cations ◽  
Mass Spectrometric ◽  
Polyethylene Glycols ◽  
Alkali Metal Cations ◽  
Secondary Ion

The mass spectrometric behaviour of mono- and di-carboxylated polyethylene glycols (PEGCs and CPEGCs) and carboxylated octylphenol ethoxylates (OPECs) is discussed. The tendency for ionisation (deprotonation, protonation and cationisation by alkali–metal cations) of carboxylated PEGs was compared with that of non-carboxylated analogues by using both secondary-ion mass spectrometry (SIMS) and electrospray ionisation (ESI). The fragmentation of the PEGCs and CPEGCs is discussed and also compared with their neutral analogues, PEGs. B/E linked-scan mass spectra were recorded, using secondary-ion mass spectrometry as a method for ion generation, for deprotonated and protonated molecules as well as for molecules cationised by alkali–metal cations. The fragmentation behaviour of PEGs is found to be different from that of CPEGCs, The presence of carboxyl groups may be confirmed not only by the determination of molecular weights of the ethoxylates studied, but also on the basis of the fragment ions formed. The metastable decomposition of the [OPEC-H]− ions proceeds through the cleavage of the bond between the octylphenol moiety and the ethoxylene chain and leads to the octylphenoxyl anions. It permits determination of the mass of the hydrophobic moiety of the studied carboxylated alkylphenol ethoxylate. ESI mass spectra recorded in the negative-ion mode were found to be more suitable than SI mass spectra for the determination of the average molecular weight of carboxylated ethoxylates.

Eine unerwartete Synthese des Triphenyphosphazenium-chlorids, [(C6H5)3PNH2]+CI– und eine Neubestimmung seiner Kristallstruktur / An Unaspected Synthesis of Triphenylphosphazenium Chloride, [(C6H5)3PNH2]+Cl– , and a Redeterm ination of its Crystal Structure

1996 ◽  
Vol 51 (6) ◽  
pp. 865-868 ◽  
Author(s):  
H. Vogt ◽  
A. Fischer ◽  
P. G. Jones
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Tetrahedral Geometry ◽  
Triclinic Space Group ◽  
Space Group

Abstract Triphenylphosphazenium chloride has been prepared by the reaction of triphenylphosphine with trimethylsilylazide in impure, wet dichloromethane. Yields are improved as stoichiometric quantities of water are added. Colourless crystals are obtained by recrystallization from the same solvent. The crystals are triclinic, space group P1̅, Z=2, a = 894,6(3), b - 979,8(3), c = 1142,9(4) pm, α = 107,27(3), β = 93,70(3), y = 92,97(3)°. In the solid state the compound exists as [(C6H5)3PNH2]+ cations, and Cl- anions. Dimeric units are formed by H-bonding. The crystal structure contains one molecule CH2Cl2 per one molecule (C6H5)3PNH2Cl. The cation has a slightly irregular tetrahedral geometry around the P-atom with a relatively short P-N bond

New Bulky Allyl Complexes of Lanthanide Metals:  Role of Alkali-Metal Cations in Controlling Solid-State and Solution Assemblies in Precatalysts

2003 ◽  
Vol 22 (15) ◽  
pp. 3028-3030 ◽  
Author(s):  
Timothy J. Woodman ◽  
Mark Schormann ◽  
David L. Hughes ◽  
Manfred Bochmann
Keyword(s):  
Solid State ◽  
Alkali Metal ◽  
Metal Cations ◽  
Alkali Metal Cations ◽  
Lanthanide Metals

scholarly journals Metallkomplexe mit Hexamethylentetramin als Ligand, VI [1] Kristallstruktur von Bis-hexamethylentetramin-bisisocyanatokupfer(II), [CU(NCO)2(C6H12N4)2] / Metal Complexes with Hexamethylenetetramine as a Ligand, VI [1J Crystal Structure of Bis-hexamethylenetetramine-bisisocyanatocopper(II), [Cu(NCO)2(C6Hl2N4)2]

1982 ◽  
Vol 37 (12) ◽  
pp. 1569-1572 ◽  
Author(s):  
Joachim Pickardt ◽  
Norbert Rautenberg
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Metal Complexes ◽  
Copper Atom ◽  
Triclinic Space Group ◽  
Space Group ◽  
Tetragonal Pyramidal

Crystals of the complex [Cu(NCO)2(C6Hi2N4)2] could be obtained by reaction of copper- (II)nitrate, hexamethylenetetramine, and KNCO in CHCI3 as a solvent. The crystals are triclinic, space group Cl, Z = 4, a = 1373.1(9), b = 2083.1(9), c = 642.6(3) pm, a = 91.05(4), β = 90.54(6), y = 107.39(6)°. The copper atom is bonded to two terminal cyanato groups via the nitrogen atoms, and to two liexamethylentetramine molecules. In the solid state the coordination of the copper atom is, however, tetragonal pyramidal, because there is an additional, rather long bond to one of the hexamethylenetetramine molecules of the neighbouring complex unit, resulting in the formation of chains

Determination of an organic crystal structure with the aid of topochemical and related considerations: correlation of the molecular and crystal structures of α-benzylidene-γ-butyrolactone and 2-benzylidenecyclopentanone with their solid state photoreactivity

1985 ◽  
Vol 397 (1812) ◽  
pp. 157-181 ◽  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Direct Methods ◽  
Nearest Neighbour ◽  
Space Group ◽  
Energy Evaluation ◽  
Evaluation Procedures ◽  
Directional Preference ◽  
The Difference

The crystal structure of α-benzylidene-γ-butyrolactone 2, can be deter­mined with the aid of atom-atom pairwise energy evaluation procedures, because its (previously reported) solid state photoreactivity coupled with topochemical principles, greatly restricts the number of possible orientations of the molecule in the unit cell. Crystals of lactone 2 are monoclinic with space group P2 1 /n and with Z = 4, a = 11.014(2), b = 5.959(1), c = 14.286(5), β = 108.05(2). Refinement on 846 non-zero reflections led to an R (reliability) of 0.046. In contrast, the isoelectronic ketone 2-benzylidenecyclopentanone (3) is photostable, and crystallizes in the same space group with Z = 4, a = 7.466(4), b = 6.821(4), c = 19.005(1), β = 94.14(1). The structure of 3 was solved by direct methods and refined on 1037 non-zero reflections to an R of 0.036. The difference between the two structures can be rationalized in terms of intramolecular conformation and weak C-H. . . O hydrogen bonding. Differences in the solid state photoreactivities of the two compounds can be related to the extent of orbital overlap between ‘potentially reactive’ double bonds on nearest neighbour molecules that are related by inversion. Compound 2 reacts in the solid state topochemically but not topotactically showing directional preference, while 3, which has reduced orbital overlap, is photostable.

Synthese und Kristallstruktur von Tribrommethyltriphenylphosphonium-bromid und Bis(tribrommethyltriphenylphosphonium)-tribroniid-bromid / Synthesis and Crystal Structure of Tribromomethyltriphenylphosphonium Bromide and Bis(tribromomethyltriphenylphosphonium) Tribromide Bromide

1995 ◽  
Vol 50 (2) ◽  
pp. 223-228 ◽  
Author(s):  
H. Vogt ◽  
C. Frauendorf ◽  
A. Fischer ◽  
P. G. Jones
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Red Light ◽  
Monoclinic Space Group ◽  
Reaction Conditions ◽  
Tetrahedral Geometry ◽  
Triclinic Space Group ◽  
Synthesis And Crystal Structure ◽  
Space Group

Tribromotriphenylphosphonium bromide 1 has been prepared by the reaction of triphenylphosphine with tetrabromomethane in dichloromethane. Colourless crystals were obtained by recrystallization from the same solvent. The light-sensitive crystals change colour to yellow. The crystals are triclinic, space group P1̄ , Z = 4, a = 1008.6(5), b = 1357.8(6), c = 1560.7(7) pm, α = 106.61(4), β = 91.80(4), γ = 93.88(4)°. In the solid state there are discrete monomeric (C6H5)3PCBr3+ cations and Br- anions. The cation has a slightly irregular tetrahedral geometry around the P atom. The crystals contain one molecule CH2C12 per four molecules (C6H5)3PCBr4.Bis(tribromomethyltriphenylphosphonium) tribromide bromide 2 can be obtained as a byproduct of the reaction of (C6H5)3P with CBr4 by variation of the reaction conditions. Red light-stable crystals are obtained by recrystallization from CH2C12. The crystals are monoclinic, space group C2/c, Z = 8, a = 2231.5(7), b = 1532.7(7), c = 1556.9(6) pm, β = 129.69(2)°. In the solid state bis(tribromomethyltriphenylphosphonium) tribromide bromide exists as discrete monomeric (C6H5)3PCBr3+ cations and Br- and Br3- anions. The Br anion and the central Br of Br3- anion lie on crystallographic twofold axes. The cation has also a slightly irregular tetrahedral geometry around the P atom, with a long P-CBr3 bond.

Sign in / Sign up

Export Citation Format

Share Document