摘要
In this text,we use inexpensive and natural amino acid,successfully obtained the asymmetric crystallization of three PTCs,[Ti6(OiPr)14(μ2-O)(μ3-O)2(D/L-pGlu)2](D-PTC-53;L-PTC-53;H2 pGlu=pyroglutamic acid)and[Ti6(OiPr)14(μ2-O)(μ3-O)2(D-pGlu)2][Ti6(OiPr)14((μ2-O)(μ3-O)2(L-pGlu)2](D,L-PTC-53).Interestingly,in situ lactamide reaction starting from glutamic acid to pyroglutamic acid was observed.In addition,the chirality features of these PTCs have been thoroughly discussed.The two enantiomers crys tallize in chiral P21 space group.The optically pure pGlu ligands transform its chirality to the inorganic titanium oxo clusters.As a result,the stack of these inorganic clusters generates homochiral helical chains along the characteristic axial direction.Apart from the microscopic structural analysis,the macroscopic solid-state samples exhibit unusual strong circular dichroism(CD)signals,further verified the homochiral feature of the enantiomers.
In this text, we use inexpensive and natural amino acid, successfully obtained the asymmetric crystallization of three PTCs, [Tis（OiPr）14（μ2-O）（μ3-O）2（D/L-pGlu）2]（D-PTC-53; L-PTC-53; H2 pGlu=pyroglutamic acid） and [Ti6（OiPr）14（μ2-O）（μ3-O）2（D-pGlu）2][Ti6（OiPr）14(（μ2-O）（μ3-O）2（L-pGlu）2]（D,L-PTC-53）. Interestingly, in situ lactamide reaction starting from glutamic acid to pyroglutamic acid was observed. In addition,the chirality features of these PTCs have been thoroughly discussed.The two enantiomers crys tallize in chiral P21 space group.The optically pure pGlu ligands transform its chirality to the inorganic titanium oxo clusters. As a result, the stack of these inorganic clusters generates homochiral helical chains along the characteristic axial direction.Apart from the microscopic structural analysis, the macroscopic solid-state samples exhibit unusual strong circular dichroism（CD） signals,further verified the homochiral feature of the enantiomers.
基金
supported by the National Natural Science Foundation of China(NSFC,Nos.21673238 and 21771181)
Youth Innovation Promotion Association CAS(No.2017345)
Natural Science Foundation of Fujian Province(Nos.2017J06009 and2017J05036)
