Search results for "TETRA"
showing 10 items of 6481 documents
Reaction of polyamines with diethyloxalate: a convenient route for the synthesis of tetraazacycloalkanes
2006
International audience; The reactivity of various polyamines with diethyloxalate has been investigated. It appears that, in similar experimental conditions, primary diamines give predominantly [2+2] adducts while the use of secondary benzylated polyamines results in [1+1] condensation. Although the intermediate tetraamides formed in the first case are extremely poorly soluble and show very slow reactivity towards reducing agents, cyclam has been obtained by using ultrasounds during the reaction of the corresponding tetraoxomacrocycle with BH 3 /THF. The [1+1] cyclization reaction of diversely N-benzylated linear tetraamines, whose selective syntheses have been devised herein, gives access t…
Ftalocyjaniny i ich rola w terapii fotodynamicznej
2017
Ftalocyjaniny to grupa ważnych i interesujących związków organicznych, otrzymywanych jedynie na drodze syntezy chemicznej, które jednak wykazują duże podobieństwo strukturalne do naturalnie występujących w przyrodzie porfiryn. Związki te posiadają unikalne właściwości fizykochemiczne, co skutkuje zastosowaniem ich w wielu różnych dziedzinach nauki począwszy od technologii, przemysłu, do medycyny. W ciągu ostatnich lat są intensywnie badane pod kątem zastosowania ich jako fotouczulaczy w terapii fotodynamicznej (PDT) z powodu posiadania szeregu korzystnych w tym aspekcie właściwości. Terapia PDT to efektywna metoda leczenia nowotworów, będąca formą światłoterapii. Zainicjowanie reakcji fotod…
Termoelektrisko īpašību pētījumi tetratiotetracēna atvasinājumu plānās kārtiņās
2018
Darbā tika izveidotas organisku pusvadītāju - tetratiotetracēna (TTT) atvasinājumu plānas kārtiņas, izmantojot termiskās iztvaicēšanas metodi vakuumā. Izmantotie atvasinājumi ir ar metil, ¬¬metoksi, fenil un izopropil grupu aizvietojumiem 2. un 8. tetratiotetracēna molekulas pozīcijā, dažādās kombinācijās. Tika pētīta plāno kārtiņu morfoloģija, izmantojot ar skenējošā elektronu mikroskopu iegūtos attēlus, kā arī termoelektriskās īpašības, nosakot to elektrisko vadītspēju un Zēbeka koeficientu. Plānās kārtiņas tika pētītas gan tīrā veidā kā arī dopētas ar jodu, iegūstot p-tipa pusvadītāja īpašības. Tika izveidots tetratiotetracēna plāno kārtiņu termoelektriskais ģenerators. Darbā ir veikti t…
2-Methylresorcinarene: a very high packing coefficient in a mono-anion based dimeric capsule and the X-ray crystal structure of the tetra-anion
2016
Mono- and tetra-deprotonated 2-methylresorcinarene anions (1 and 2) as their trans-1,4-diammoniumcyclohexane (TDAC)2+ inclusion complexes are reported. The mono-anion forms a fully closed dimeric capsule [1·H2O·MeOH]22− with a cavity volume of 165 Å3 and (TDAC)2+ as the guest with an extremely high packing coefficient, PC = 84.2%, while the tetra-anion forms a close-packed structure with two structurally isomeric tetra-anions 2a and 2b with a 50 : 50 ratio in the crystal lattice. peerReviewed
CCDC 662715: Experimental Crystal Structure Determination
2008
Related Article: J.Bould, A.Laromaine, N.J.Bullen, C.Vinas, M.Thornton-Pett, R.Sillanpaa, R.Kivekas, J.D.Kennedy, F.Teixidor|2008|Dalton Trans.||1552|doi:10.1039/b715845a
CCDC 1958345: Experimental Crystal Structure Determination
2020
Related Article: Raphael C. A. Vaz, Isabela O. Esteves, Willian X. C. Oliveira, João Honorato, Felipe T. Martins, Lippy F. Marques, Guilherme L. dos Santos, Ricardo O. Freire, Larissa T. Jesus, Emerson F. Pedroso, Wallace C. Nunes, Miguel Julve, Cynthia L. M. Pereira|2020|Dalton Trans.|49|16106|doi:10.1039/D0DT02497J
Synteza i charakterystyka spektralna oktakarboksyftalocyjanin metali
2017
Przedstawiona praca dotyczy metod syntezy oktakarboksyftalocyjanin cynku, glinu i galu oraz ich charakterystyki spektralnej (spektroskopii UV-Vis), którą przestawiono zarówno z punktu widzenia eksperymentalnego, jak i teoretycznego. Opisano istniejące metody syntezy ftalocyjanin i ich modyfikacje prowadzące do uzyskania pochodnych rozpuszczalnych w wodzie, mających jako podstawniki peryferyjne osiem grup karboksylowych. Scharakteryzowano widma absorpcyjne UV- Vis typowe dla ftalocyjanin, dzięki którym można uzyskać wiele cennych informacji na temat tych kompleksów. Ponadto przeprowadzono obliczenia absorpcyjnych widm UV oktakarbosyftalocyjaniny cynku w ramach zależnej od czasu metody funkcj…
Spin Crossover in Fe(II)–M(II) Cyanoheterobimetallic Frameworks (M = Ni, Pd, Pt) with 2-Substituted Pyrazines
2016
Discovery of spin-crossover (SCO) behavior in the family of Fe(II)-based Hofmann clathrates has led to a "new rush" in the field of bistable molecular materials. To date this class of SCO complexes is represented by several dozens of individual compounds, and areas of their potential application steadily increase. Starting from Fe(2+), square planar tetracyanometalates M(II)(CN)4(2-) (M(II) = Ni, Pd, Pt) and 2-substituted pyrazines Xpz (X = Cl, Me, I) as coligands we obtained a series of nine new Hofmann clathrate-like coordination frameworks. X-ray diffraction reveals that in these complexes Fe(II) ion has a pseudo-octahedral coordination environment supported by four μ4-tetracyanometallat…
The N-dimensional N-person chesslike game strategy analysis model
2016
In this research a mathematical, symmetric n-player game model, based on chess is designed. Symmetry in this context refers to players' positions with respect to each other. While the order of move naturally violates the symmetry, this problem may also be solved. The motivation for building this kind of game model stems from the difficulty of finding mathematical solutions for multi-player games in general. The number of varying factors is so huge, that finding optimal strategies is mathematically almost impossible. The best way to attempt this is to use simulation. Once the model has been built, it can be applied in many ways by using computational algorithms based on the created model. Ch…
Weak Interactions between Trivalent Pnictogen Centers: Computational Analysis of Bonding in Dimers X3E···EX3 (E = Pnictogen, X = Halogen)
2009
The nature of weak interactions in dimers X3E···EX3 (E = N−Bi, X = F−I) was investigated by wave function and density functional theory (DFT)-based methods. Out of the 20 systems studied, 10 are found to be bound at the CP-MP2 and LMP2 levels of theory. Detailed partition of the interaction energy into different components revealed that dispersion is the primary force holding the dimers together but there also exists an important ionic component whose contribution increases with increasing halogen size. As expected, standard density functionals fail to describe bonding in the studied systems. However, the performance of DFT methods can be easily improved via empirical dispersion correction …