منابع مشابه
Bond distances in polypeptide backbones depend on the local conformation.
By combining quantum-mechanical analysis of small model peptides and statistical surveys of high-resolution protein structures, a systematic conformational dependence of bond lengths in polypeptide backbones has been unveiled which involves both the peptide bond (C-O and C-N) and those bonds centred on the C(α) atom. All of these bond lengths indeed display a systematic variability in the ψ ang...
متن کاملDetermination of Molybdenum - Oxygen Bond Distances and Bond Orders by Raman Spectroscopy
A correlation is developed for relating Rarnan stretching frequencies of molybdenum-oxygen ( M 4 ) bonds to their respective bond distances in molybdenum oxide compounds. M+O bond orders are also related to Stretching frequencies. The M 4 correlation is expected to offer invaluable insight into the structures of rnolybdate species in chemical systems which are not amenable to analysis by difkac...
متن کاملDetermination of niobium-oxygen bond distances and bond orders by Raman spectroscopy
An empirical correlation is established for relating Raman stretching frequencies of niobium-oxygen (Nb-O) bonds to their respective bond distances in niobium oxide compounds. The correlation is an exponential least-squares fit between measured Raman frequencies and reported crystallographic bond lengths. Niobium-oxygen bond strengths (in valence units) are also related to Raman stretching freq...
متن کاملAn aqua-adenine H-bonding interaction controlling the formation of the rare Zn(II)–N9(adenine) bond in crystal structure of diaqua(adenine)(iminodiacetato)zinc(II)
A novel mixed-ligand zinc(II) complex with iminodiacetato(2-) (IDA) and adenine (AdeH) ligands has been obtained. Its crystal consists of octahedral molecules [Zn(IDA)(AdeH)(H2O)2] where the selective Zn–N9(AdeH) bond, involving the most basic N(AdeH) donor atom, occupies the trans position versus the Zn–N(IDA) bond. The Zn(II)–N9(AdeH) binding mode seems to be rare enough in comparison to thos...
متن کاملSynthesis, cyclopolymerization and cyclo-copolymerization of 9-(2-diallylaminoethyl)adenine and its hydrochloride salt.
We report herein the synthesis and characterization of 9-(2-diallylaminoethyl) adenine. We evaluated two different synthetic routes starting with adenine where the optimal route was achieved through coupling of 9-(2-chloroethyl)adenine with diallylamine. The cyclopolymerization and cyclo-copolymerization of 9-(2-diallylaminoethyl)adenine hydrochloride salt resulted in low molecular weight oligo...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Nature
سال: 1949
ISSN: 0028-0836,1476-4687
DOI: 10.1038/164750a0