RESUMO
In the search for synthetic mimics of protein secondary structures relevant to the mediation of protein-protein interactions, we have synthesized a series of tetrasubstituted diphenylacetylenes that display ß-sheet structures in two directions. Extensive X-ray crystallographic and NMR solution phase studies are consistent with these proteomimetics adopting sheet structures, displaying both hydrophobic and hydrophilic amino acid side chains.
Assuntos
Acetileno/análogos & derivados , Acetileno/química , Cristalografia por Raios X , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Peptídeos/química , Dobramento de Proteína , Desdobramento de ProteínaRESUMO
Synthetic molecules capable of the mimicry of α-helices that are elongated and/or contain hydrophilic side chains have been largely elusive. However, the oligophenylenaminone structure can surmount both of these challenges (see scheme).
RESUMO
A family of planar disc-like hexa-, octa- and decametallic Ni(II) complexes exhibit dominant ferromagnetic exchange. The deca- and octametallic clusters [Ni(II) (10)(tmp)(2)(N(3))(8)(acac)(6)(MeOH)(6)] (1, H(3)tmp=1,1,1-tris(hydroxymethyl)propane; acac=acetylacetonate) and [Ni(II) (8)(thme)(2)(O(2)CPh)(4)(Cl)(6)(MeCN)(6)(H(2)O)(2)] (2, H(3)thme=1,1,1-tris(hydroxymethyl)ethane) represent rare examples of Ni(II)-based single-molecule magnets, and [Ni(II) (10)] (1) possesses the largest barrier to magnetisation reversal of any Ni(II) single-molecule magnet to date.
RESUMO
Ferromagnetic exchange between the three Mn ions in the complex [Mn3(Hcht)2(bpy)4](ClO4)3 leads to a spin ground state of S = 7; single crystal studies reveal the temperature and sweep rate dependent hysteresis loops expected for a single-molecule magnet.
Assuntos
Magnetismo , Manganês/química , Compostos Organometálicos/química , Compostos Organometálicos/síntese química , Cristalografia por Raios X , Modelos Moleculares , Estrutura Molecular , TemperaturaRESUMO
We describe the design and synthesis of a non-peptidic ß-strand mimetic composed of alternating aryl and imidazolidin-2-one rings that can be adapted to display diverse side-chains. Solid- and solution-phase data together with calculations suggest that the desired conformation for side-chain mimicry is readily accessible and well-populated.
Assuntos
Materiais Biomiméticos/química , Imidazolidinas/química , Materiais Biomiméticos/síntese química , Cristalografia por Raios X , Espectroscopia de Ressonância Magnética , Conformação Molecular , Peptídeos/química , Soluções/químicaRESUMO
[Mn(IV)Mn(II)3] triangular units directed by the presence of tripodal alcohols self-assemble in the presence of azide and acetate ligands to form either a [Mn24] "wheel" or a [Mn32] "cube".