Search results for "LIX"

CCDC 1938871: Experimental Crystal Structure Determination

2020

Related Article: S. Maryamdokht Taimoory, Kwaku Twum, Mohadeseh Dashti, Fangfang Pan, Manu Lahtinen, Kari Rissanen, Rakesh Puttreddy, John F. Trant, Ngong Kodiah Beyeh|2020|J.Org.Chem.|85|5884|doi:10.1021/acs.joc.0c00220

CCDC 1966171: Experimental Crystal Structure Determination

2020

Related Article: Kwaku Twum, J. Mikko Rautiainen, Shilin Yu, Khai-Nghi Truong, Jordan Feder, Kari Rissanen, Rakesh Puttreddy, Ngong Kodiah Beyeh|2020|Cryst.Growth Des.|20|2367|doi:10.1021/acs.cgd.9b01540

CCDC 282424: Experimental Crystal Structure Determination

2006

Related Article: H.Mansikkamaki, S.Busi, M.Nissinen, A.Ahman, K.Rissanen|2006|Chem.-Eur.J.|12|4289|doi:10.1002/chem.200501201

Stepwise synthesis and selective dimerisation of bis- and trisloop tetra-urea calix[4]arenes.

2008

Tetra-urea calix[4]arenes substituted with four mono- or bisalkenyl residues have been converted into bis- or tetraloop compounds by intramolecular olefin metathesis, with use of a tetratosylurea calix[4]arene as template. The same strategy has now been used to synthesise trisloop compounds and bisloop compounds with adjacent loops, completing the series of the loop-containing tetra-urea derivatives. A tetra-urea calix[4]arene of the AABB type, where A stands for a bisalkenyl- and B for a monoalkenyl-substituted urea unit, was used as precursor for the three loops. It was easily synthesised from a tetraamino calix[4]arene in which two adjacent amino groups were Boc-protected. The ABCB-type …

ChemInform Abstract: Chirality in Calixarenes and Calixarene Assemblies

2001

The synthesis of double-calixarenes

1989

Abstract Macrocyclic molecules consisting of two calix[4]arene moieties linked via their p-positions by one 1, two 2 or four 3 aliphatic chains were synthetized for the first time.

A Hydrogen-Bonded Supramolecular meso-Helix

2003

[EN] A new one-dimensional hydrogen-bonded polymer with a unique meso-helical structure has been prepared from the spontaneous self-assembly in the solid-state of meta-substituted phenylene dioxamic acid diethyl ester monomers. The helical nature of this molecule and its self-complementary character, through intermolecular hydrogen bonding between oxamic acid ester functions, are the two main factors responsible for the crystalline aggregation process, as confirmed by both experimental X-ray crystallographic data and theoretical ab initio calculations.

Bis-ferrocene derivatives of bridged calix[4]arenes: syntheis, X-ray crystal structure and electrochemical properties

1991

The reaction of chlorocarbonylferrocene (2) with bridged calix[4]arene macrocyclic compounds, in which two opposite para-positions are connected by an additional aliphatic chain where n = 5 (1a) or n = 8 (1b) respectively, gave the corresponding new redox-active bis-ferrocene derivatives of bridged calix[4]arenes, 3a and 3b. An X-ray diffraction study of 3a shows that the caliz[4]arene has a cone conformation in which the two ferrocene substituents are located on the phenolic units connected to each other by the aliphatic chain bridge. Cyclic voltammetric and coulometric studies in dichloromethane reveal that 3a and 3b undergo reversible two electron oxidations at + 0.90 V (versus SCE), sug…

Compensation of steric demand by cation–π interactions, cobaltocenium cations as guests in tetraurea calix[4]arene dimers

2003

The affinities of ferrocene (2) and the cobaltocenium cation (3+), which have roughly the same size and differ in their charge, towards the inner cavity of the dimeric capsule formed by tetraurea calix[4]arene (1) were studied in C2D4Cl2 solutions. While 3+, which occupies more than 75% of the internal volume of the dimer, is readily encapsulated this is not the case for 2. This is probably due to cation-pi interactions, which operate only between 3+ and the aromatic rings of the calix[4]arene dimer. We found that the affinity of the cobaltocenium cation is higher than that of the tropylium cation (4+) and is only 2-3 times less than that of the tetraethylammoniun cation (5+). From the vari…

Noncovalent assembly of functional groups on calix[4]arene molecular boxes

1997

Calix[4]arenes diametrically substituted at the upper rim with two melamine units spontaneously form well-defined box-like assemblies in the presence of two equivalents of 5,5-diethylbarbituric acid. These assemblies, consisting of nine different components, are held together by 36 hydrogen bonds and are stable in apolar solvents at concentrations of up to 10-4M. This paper reports the first X-ray crystal structure, and the MALDI TOF mass spectra together with the complete 1H NMR spectroscopic characterization of these hydrogen-bonded assemblies. The crystal structure clearly shows that the assemblies are stereogenic, as a result of the antiparallel orientation of the two rosette motifs. Fu…