Tetrakis(methylimidazole) and tetrakis(methylimidazolium) calix[4]arenes: competitive anion binding and deprotonation.

نویسندگان

  • Emma K Bullough
  • Colin A Kilner
  • Marc A Little
  • Charlotte E Willans
چکیده

Neutral tetrakis(methylimidazole) (1) and the novel cationic tetrakis(methylimidazolium) (2) calixarenes have been prepared and their solid-state and solution behaviour examined. The neutral imidazole forms a mono-zwitterion at elevated temperature, a feature that has been observed both in solution and in the solid-state. The cationic imidazolium exhibits a range of hydrogen bond interactions with anions, with the titration curves upon binding to basic anions suggesting sequential binding to both the upper and lower rims.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Voltage-dependent block of endothelial volume-regulated anion channels by calix[4]arenes.

We have studied the effects of calix[4]arenes on the volume-regulated anion channel (VRAC) currents in cultured calf pulmonary artery endothelial cells. TS- and TS-TM-calix[4]arenes induced a fast inhibition at positive potentials but were ineffective at negative potentials. Maximal block occurred at potentials between 30 and 50 mV. Lowering extracellular pH enhanced the block and shifted the m...

متن کامل

Synthesis of a Novel Calix[4]resorcinarene-Chitosan Hybrid

Synthesis of a novel calix[4]resorcinarene-chitosan hybrid using vanillin as raw material has been conducted. The synthesis was carried out in four steps i.e. (1) allylation of vanillin, (2) HCl-catalyzed condensation allyl vanillin with resorcinol, (3) chloromethylation of C-4-allyloxy-3-methoxyphenylcalix[4] resorcinarene with paraformaldehyde and HCl in the presence of ZnCl 2 to yield tetrak...

متن کامل

Thermodynamics Binding of Tetrakis (2,3,5,6-Tetrafluoro-N,N′,Nʺ-Trimethyl Ammonium Phenyl) Porphyrin Nickel(II) With Calf Thymus DNA

In this study, aggregation behavior of a water soluble cationic metalloporphyrin, meso-tetrakis (2,3,5,6-tetrafluoro-N,N´,N´´-trimethyl ammonium phenyl) porphyrin nickel(II) [Ni(II)(TF4TMAPP)]4+ is investigated in 5 mM aqueous phosphate buffer of pH 7.0 at 25.0 °C and various ionic strengths using optical absorption and resonance light scattering spectroscopic methods. The...

متن کامل

Conformationally switchable non-cyclic tetrapyrrole receptors: synthesis of tetrakis(1H-pyrrole-2-carbaldehyde) derivatives and their anion binding properties.

A series of tetrakis(1H-pyrrole-2-carbaldehyde) receptors (2, 4, and 6) were synthesized in two steps from commercially available starting materials. The anion binding properties of these receptors can be tuned through electronic switching to stabilize a conformation displaying high affinity for the dihydrogenphosphate and pyrophosphate anions (as the tetrabutylammonium salts) in chloroform.

متن کامل

Synthesis and anion binding studies of o-phenylenevinylene-bridged tetrapyrrolic macrocycle as an expanded analogue of calix[4]pyrrole.

An o-phenylenevinylene-bridged tetrapyrrolic macrocycle (2) was synthesized by means of a Horner-Wadsworth-Emmons reaction between benzylbisphosphonate and SEM-protected diformylpyrrole, followed by deprotection of the SEM groups. This conformationally flexible tetrapyrrole can be considered as an expanded calix[4]pyrrole analogue, which acts as a receptor for the chloride and bromide anions in...

متن کامل

ذخیره در منابع من

ذخیره در منابع من قبلا به منابع من ذحیره شده

{@ msg_add @}


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • Organic & biomolecular chemistry

دوره 10 14  شماره 

صفحات  -

تاریخ انتشار 2012