Search results for "diene"
showing 10 items of 623 documents
CCDC 249547: Experimental Crystal Structure Determination
2005
Related Article: M.Viciano, E.Mas-Marza, M.Poyatos, M.Sanau, R.H.Crabtree, E.Peris|2005|Angew.Chem.,Int.Ed.|44|444|doi:10.1002/anie.200461918
Cd(II) and Cu(II) coordination polymers constructed from the expanded 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene ligand: conventional and ultrasound-…
2018
Shaabani, Behrouz/0000-0001-5576-4604; Kubicki, Maciej/0000-0001-7202-9169; Grzeskiewicz, Anita M./0000-0003-0377-2260 WOS: 000447971700041 A 3D open inorganic/organic framework, {[Cd(mu-L)(mu(3)-SO4)(H2O)]center dot H2O}(n) (1) [L = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene] was synthesized by the reaction of CdSO4 center dot 8H(2)O with L. The treatment of Cu(NO3)(2)center dot 3H(2)O with the same N,N'-donor ligand in two different solvent mixtures, methanol/ dichloromethane (2) and methanol/ chloroform (3), afforded two new ladder-like coordination polymers of formula {[Cu(mu-L)(mu-NO3)(NO3)]center dot solv}(n) [solv = CH2Cl2 (2) and CHCl3 (3)]. The non-interpenetrated ladder motifs 2 a…
Chlamydomonas reinhardtii in the landscape of pigments.
2004
▪ Abstract This review focuses on the biosynthesis of pigments in the unicellular alga Chlamydomonas reinhardtii and their physiological and regulatory functions in the context of information gathered from studies of other photosynthetic organisms. C. reinhardtii is serving as an important model organism for studies of photosynthesis and the pigments associated with the photosynthetic apparatus. Despite extensive information pertaining to the biosynthetic pathways critical for making chlorophylls and carotenoids, we are just beginning to understand the control of these pathways, the coordination between pigment and apoprotein synthesis, and the interactions between the activities of these…
Liquid/Gas and Liquid/Liquid Phase Behavior of n-Butane/1,4-Polybutadiene versus n-Butane/1,2-Polybutadiene
2005
Solutions of 1,4-polybutadiene (1,4-PB, 98% cis) and of 1,2-polybutadiene (1,2-PB) in n-butane (n-C 4 ) were studied with respect to their vapor pressure and to their demixing into two liquid phases under isochoric conditions within the temperature range from 25 to 75 °C. 1,2-PB mixes homogeneously with n-C 4 at any ratio, in contrast to 1,4-PB, which exhibits a miscibility gap extending from practically pure solvent to approximately 40 wt % polymer. Corresponding to these solubility differences, the vapor pressures for the system n-C 4 /1,4-PB are considerably higher than for n-C 4 /1,2-PB at the same concentration and temperature. The experimental results are modeled accurately and consis…
Pauson-Khand reaction of internal dissymmetric trifluoromethyl alkynes. Influence of the alkene on the regioselectivity.
2014
Abstract: The scope of the Pauson-Khand reaction (PKR) of internal trifluoromethyl alkynes, previously described with norbornadiene, is expanded to norbornene and ethylene. A thorough structural analysis of the resulting PK adducts has been carried out to unveil that α-trifluoromethylcyclopentenones are preferred in all cases, independently of the electronic properties of the alkyne. The regioselectivity observed with norbornadiene and ethylene is higher than in the case of norbornene.
Valsts probācijas dienesta funkcija- izlīguma organizēšana un vadīšana kriminālprocesā ar starpnieka palīdzību
2015
Noziedzīga nodarījuma rezultātā likumpārkāpējs ir radījis kaitējumu noteiktai personai – cietušajam. Sabiedrībā valda uzskats, ka likumpārkāpēju var sodīt tikai bargs sods, bet ne vienmēr tas ir labākais risinājums. Bieži vien labs risinājums ir izlīgums, kas noslēgts starp cietušo un likumpārkāpēju. Izlīguma rezultātā likumpārkāpējs atzīst savu vainu, bet cietušais gūst gan morālu, gan finansiālu mierinājumu un atzīst, ka pēc izlīguma noslēgšanas viņam nav prasību pret likumpārkāpēju. Izlīgumā iesaistītās puses ar starpnieka palīdzību sarunu ceļā risina radušos konfliktu. Likumpārkāpējam bieži var būt pat smagāk satikt un uzklausīt cietušo klātienē, nekā izciest tiesas piespriesto sodu, tā…
Reptation and constraint release
1991
Abstract The reptation and constraint release models are discussed by considering three recent experimental examples: (1) the diffusion of hydrogenated polybutadiene in matrices of molecular weights raning between 1 ⩽ Mw / Me ⩽ 253; (2) the diffusion of polystyrene (PS) chains in matrices of star branched PS; (3) the diffusion of very long PS chains in chemically cross-linked PS-networks. It is concluded that the reptation and constraint release models are applicable, but ‘constraint release’ should be understood in a wider sense allowing for non-reptative removal of barriers to lateral chain motion. The analysis of the third example proves that lateral modes of motion have a negligible inf…
Intramolecular caging in polybutadiene due to rotational barriers
2003
We present molecular dynamics simulations of a chemically realistic model of 1,4-polybutadiene and a freely rotating chain model derived from the first model by neglecting all dihedral potentials. We show that the presence of energy barriers hindering dihedral rotation leads to an intermediate plateau regime in the tagged particle mean-squared displacement reminiscent of the cage effect underlying the mode-coupling description of the liquid-glass transition. This intramolecular caging, however, occurs already at temperatures well above the glass transition regime. Because of its different physical origin, it also does not comply with the theoretical predictions of the mode-coupling theory. …
Exploring the Heterogeneity and Trajectories of Positive Functioning Variables, Emotional Distress, and Post-traumatic Growth During Strict Confineme…
2022
Abstract COVID-19 pandemic-related confinement may be a fruitful opportunity to use individual resources to deal with it or experience psychological functioning changes. This study aimed to analyze the evolution of different psychological variables during the first coronavirus wave to identify the different psychological response clusters, as well as to keep a follow-up on the changes among these clusters. The sample included 459 Spanish residents (77.8% female, Mage = 35.21 years, SDage = 13.00). Participants completed several online self-reported questionnaires to assess positive functioning variables (MLQ, Steger et al. in J Loss Trauma 13(6):511–527, 2006. 10.1080/15325020802173660; GQ…
4,4-Bis(4-methylphenylsulfanyl)-1,1-diphenyl-2-azabuta-1,3-diene
2007
In the title compound, C29H25NS2, both the Cl atoms of the azadiene precursor 4,4-dichloro-1,1-diphenyl-2-azabuta-1,3-diene are replaced by two vicinal S-p-tolyl substituents attached to the terminal C atom of a π-conjugated 2-azabutadiene array. The azadiene chain is planar to within 0.01 Å. One of the phenyl rings seems to be slightly π-conjugated with the azadiene core [dihedral angle 5.1 (2)°].