From calcium interaction to calcium electrochemical detection by [(C5H5)Fe(C5H4COCH=CHC6H4NEt2)] and its two novel structurally characterized derivatives

[(C(5)H(5))Fe(C(5)H(4)COCH=CHC(6)H(4)NEt(2))] (1) has been electrochemically evaluated toward different cations in solution. Calcium sensing by this compound and its two new derivatives [(C(5)H(5))Fe(C(5)H(4)CO(CH=CH)(2)C(6)H(4)NMe(2))] (2) and [(C(5)H(5))Fe(C(5)H(4)CH=CHCOCH=CHC(6)H(4)NEt(2))] (3) that exhibit a conjugated link between the ferrocene unit and the nitrogen atom has been thoroughly examined. Compounds 2 and 3 have been structurally characterized by single-crystal X-ray diffraction studies. The three related protonated species [1H][BF(4)] (4), [2H][BF(4)] (5), and [3H][BF(4)] (6) have been isolated in a good yield. NMR experiments clearly established that calcium interaction occurs in the vicinity of the carbonyl group, and mass spectrometry studies confirmed that this interaction, which involves several ligand-Ca(2+) adducts, is complex. A combination of electrochemical and NMR experiments highlighted an original salt influence on the electrochemical calcium sensing result.     

Simple isotopic product rules valid for absolute and integrated infrared intensities

Microwave spectra of CH¹⁸ OCOOH, CHOC¹⁸ OOH, CHOCO¹⁸ OH, ¹³ CHOCOOH and CHO¹³ COOH are reported and have been used in combination with data on CHOCOOH and CHOCOOD to determine the molecular structure as r(C=O)_ald. = 1.174 ± 0.006 Å, r(C=O)_acid = 1.203 ±0.006 Å, r(C—O) = 1.313 ± 0.010 Å, r(C—C) = 1.535 ± 0.005 Å, r(O—H) = 0.948 ± 0.004 Å, r(C—H) = 1.104 ±0.010 Å, ald. = 123.7 ± 0.4<, 相似文献   

Quaterthiophene-based dimers containing an ethylene bridge: molecular design,synthesis, and optoelectronic properties

Two quaterthiophene-based dimers including an ethylene bridge have been designed and efficiently prepared; experimental and computational studies show a promising potential as semiconducting material with a charge transport of higher dimensionality compared to quaterthiophene.     

Periodic schedules for linear precedence constraints

We consider the computation of periodic cyclic schedules for linear precedence constraints graphs: a linear precedence constraint is defined between two tasks and induces an infinite set of usual precedence constraints between their executions such that the difference of iterations is a linear function. The objective function is the minimization of the maximal period of a task.We recall first that this problem may be modelled using linear programming. A polynomial algorithm is then developed to solve it for a particular class of linear precedence graphs called unitary graphs. We also show that a periodic schedule may not exist for unitary graphs. In the general case, a decomposition of the linear precedence graph into unitary components is computed and we assume that a periodic schedule exists for each of these components. Lower bounds on the periods are exhibited and we show that an optimal periodic schedule may not achieve them. The notion of quasi-periodic schedule is then introduced and we prove that this new class of schedules always reaches these bounds.