نتایج جستجو برای: π delocalization
تعداد نتایج: 35852 فیلتر نتایج به سال:
The title mol-ecule, C(8)H(6)BrNS(2), is almost planar with a dihedral angle of 0.9 (1)° between the benzene and thia-zole rings. The values of the geometry-based index of aromaticity (HOMA) and the nucleus-independent chemical shift (NICS) for the two cyclic fragments of the title mol-ecule are 0.95 and -9.61, respectively, for the benzene ring, and 0.69 and -7.71, respectively, for the thia-z...
A formal gold-for-chromium transmetalation allowed the gold carbenoid species [Cy3 PAuCAr2 ]NTf2 (11) (Ar=pMeOC6 H4 -) to be obtained in crystalline form. The structure in the solid state suggests that there is only little back donation of electron density from gold to the carbene center of 11 and hence very modest AuC double-bond character; rather, it is the organic ligand framework that is r...
A new hexaazatriphenylene (HAT) derivative formed by the fusion of three HAT units has been prepared and its electronic and molecular structures have been fully characterized by optical and vibrational Raman spectroscopy, electrochemistry, solid-state UV and inverse photoemission spectroscopy (UPS and IPES), and by quantum-chemical calculations. A comparative HAT versus tri-HAT study was perfor...
In the title compound, C(20)H(18)N(2)O, the pyrazole ring adopts a planar conformation. The C-N bond lengths in the pyrazole ring are shorter than a standard C-N single bond (1.443 Å), but longer than a standard double bond (1.269 Å), indicating electron delocalization. The propenal group assumes an extended conformation. Inter-molecular C-H⋯O hydrogen bonds connect mol-ecules into cyclic centr...
The title salt, C(3)H(10)N(+)·C(14)H(8)F(3)O(2) (-), constitutes the first organic crystal containing a residue of 4,4,4-trifluoro-1-(naphthalen-2-yl)butane-1,3-dione. The terminal -CF(3) group is disordered over two locations [occupancy ratio = 0.830 (7):0.170 (7)]. Bond delocalization involving the two carbonyl groups and the α-carbon was observed. The crystal packing is mediated by several s...
A novel, star-shaped electron acceptor, DMTPA-PDI3, derived from a planar dimethylmethylene-bridged triphenylamine core with three acetylene-linked perylene diimide (PDI) units is developed as a nonfullerene acceptor for organic solar cells (OSCs). DMTPA-PDI3 manifests significantly reduced intramolecular twisting, enabling sufficient system-wide π-electron delocalization leading to broadened s...
در بخش تجربی این پروژه با رویکرد مهندسی کریستال نسبت به سنتز و شناسایی ساختار لیگاند کربوکسامیدی l (n- (2-پیرازین)- تیوفن-2-کربوکسامید) و کمپلکس های سری هالید جیوه (ii) این لیگاند اقدام گردید. بررسی ساختارهای ابرمولکولی این ترکیب ها نشان می دهد که تشکیل پیوند های هیدروژنی کلاسیک n-h...n و برهم کنش های غیرکووالانسی ضعیف π...π (در مورد لیگاند آزاد l) و c-h...π (در کمپلکس های 2 و 3) بین حلقه های آ...
A molecular water oxidation catalyst based on the copper complex of general formula [(Lpy)CuII]2-, 22-, (Lpy is 4-pyrenyl-1,2-phenylenebis(oxamidate) ligand) has been rationally designed and prepared to support a more extended π-conjugation through its structure in contrast with its homologue, the [(L)CuII]2- water oxidation catalyst, 12- (L is o-phenylenebis(oxamidate)). The catalytic performa...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید