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1.
A porphyrin-DNA complex in which helical porphyrin assemblies were stacked as π-stacked aggregates on a DNA scaffold was found. The complex indicates the inversions of optical rotation by only the control of ionic equilibrium without any structural changes of DNA scaffold. 相似文献
2.
1 INTRODUCTION Orotic acid (H3dtpc), an important pyrimidine derivative as the effective precursor in the biosynthesis of pyrimidine base of nucleic acids in living organisms, plays a unique role in bioinorganic and pharmaceutical. Aside from the biological interest, orotic acid is also interesting in coordination chemistry. Its ketonic and enolic tautomers along with asymmetric geometry make it to be a very good versatile polydentate ligand[1~5]. The incorporation of metals into supram… 相似文献
3.
Jean Weiss 《Journal of inclusion phenomena and macrocyclic chemistry》2001,40(1-2):1-22
The tremendous efforts made in order to control the coordination chemistry of hemoprotein models have considerably enhanced the synthesis of functionalized porphyrins, whose carefully designed architectures allowed for selective bindings of exogenic substrates. The common use of zinc(II) in place of pentacoordinated iron(II) has induced the use of zinc(II) porphyrins as building blocks for selective receptors. These receptors offer a convenient combination of multi-point recognition of substrates, and monitoring of the complexation due to the chromophoric nature of the tetrapyrrolic unit. This review is dedicated to recent progress made in the field of molecular recognition involving multi-point selective binding processes, in whichthe establishment of a strong coordination bond is finely tuned by one or more weak interactions adequately introduced in the architecture of a functionalized zinc(II)-porphyrin. 相似文献
4.
The Role of Torsional Dynamics on Hole and Exciton Stabilization in π‐Stacked Assemblies: Design of Rigid Torsionomers of a Cofacial Bifluorene 下载免费PDF全文
Dr. Denan Wang Dr. Maxim V. Ivanov Dr. Damian Kokkin John Loman Jin‐Zhe Cai Prof. Scott A. Reid Prof. Rajendra Rathore 《Angewandte Chemie (International ed. in English)》2018,57(27):8189-8193
Exciton and charge delocalization across π‐stacked assemblies is of importance in biological systems and functional polymeric materials. To examine the requirements for exciton and hole stabilization, cofacial bifluorene ( F 2) torsionomers were designed, synthesized, and characterized: unhindered (model) Me F 2, sterically hindered tBu F 2, and cyclophane‐like C F 2, where fluorenes are locked in a perfect sandwich orientation via two methylene linkers. This set of bichromophores with varied torsional rigidity and orbital overlap shows that exciton stabilization requires a perfect sandwich‐like arrangement, as seen by strong excimeric‐like emission only in C F 2 and Me F 2. In contrast, hole delocalization is less geometrically restrictive and occurs even in sterically hindered tBu F 2, as judged by 160 mV hole stabilization and a near‐IR band in the spectrum of its cation radical. These findings underscore the diverse requirements for charge and energy delocalization across π‐stacked assemblies. 相似文献
5.
Isabella Karle Richard D. Gilardi Ch. Chandrashekhar Rao K.M. Muraleedharan Subramania Ranganathan 《Journal of chemical crystallography》2003,33(10):727-749
Benzenehexacarboxylic acid, mellitic acid (MA), has been used as a core motif to study possible radial self-assembly using complementary aromatic bases. By mixing water solutions of the components, crystals of the salts of MA with 4-aminopyridine (AP), 4-dimethylamino-pyridine (DM), 2,2-bipyridine (DP), o-phenanthroline (PL), and melamine (ML) have been obtained. The MA–n
ions have assembled in either extended sheets for MA–2 or extended ribbons for MA–4 by direct hydrogen bonding between MA and MA and additionally through mediation of hydrogen bonds to water molecules that distribute the negative charges throughout the MA sheet or ribbon. Most of the O atoms in carboxyl groups in the MA ions in the five complexes have been rotated significantly out of the plane of the central benzene ring. There are multiple base molecules, two or four, for each mellitic acid ion in the five complexes. Most of the NH+ moieties in all five bases make direct NH+ O–C hydrogen bonds with MA–n
. The planar base ions are generally arranged in stacks in which the components range from being parallel, with interplanar separations of 3.5 Å, to having a considerable tilt with respect to each other with nearest interplanar separation of atoms greater than 3.9 Å. These geometric characteristics are reflected in the color of the crystals. The three-dimensional networking makes some of the crystals very hard. Cell dimensions: 1, C32H30N8O12 2H2O, C2/c, a =13.764(2) Å, b =18.053(3) Å, c =14.876(4) Å, =105.99(2)° 2, C26H26N4O12 3H2O, P21/n, a =15.891(1) Å, b =10.444(1) Å, c =18.242(1) Å, =97.00(1); 3, C64H44N8O24
7H2O, P21/c, a =23.016(4) Å, b =15.241(2) Å, c =19.124(2) Å, =100.60(1)° 4, C36H22N4O12, P21/n, a =14.581(1) Å, b =10.472(1) Å, c =20.607(2) Å, =106.43(1); 5, C18H18N12O12 2H2O,
, a =8.257(2) Å, b =8.986(2) Å, c =9.383(1) Å, =98.60(1)°, =96.38(2)°, =117.07(1)°. 相似文献
6.
7.
From Intramolecular (Circular) in an Isolated Molecule to Intermolecular Hole Delocalization in a Two‐Dimensional Solid‐State Assembly: The Case of Pillarene 下载免费PDF全文
Dr. Maxim V. Ivanov Dr. Denan Wang Dr. Tushar S. Navale Dr. Sergey V. Lindeman Prof. Rajendra Rathore 《Angewandte Chemie (International ed. in English)》2018,57(8):2144-2149
To achieve long‐range charge transport/separation and, in turn, bolster the efficiency of modern photovoltaic devices, new molecular scaffolds are needed that can self‐assemble in two‐dimensional (2D) arrays while maintaining both intra‐ and intermolecular electronic coupling. In an isolated molecule of pillarene, a single hole delocalizes intramolecularly via hopping amongst the circularly arrayed hydroquinone ether rings. The crystallization of pillarene cation radical produces a 2D self‐assembly with three intermolecular dimeric (sandwich‐like) contacts. Surprisingly, each pillarene in the crystal lattice bears a fractional formal charge of +1.5. This unusual stoichiometry of oxidized pillarene in crystals arises from effective charge distribution within the 2D array via an interplay of intra‐ and intermolecular electronic couplings. This important finding is expected to help advance the rational design of efficient solid‐state materials for long‐range charge transfer. 相似文献
8.
Pei Hongxia Lu Sheming Ke Yanxiong Li Jianmin Qin Shoubo Zhou Shuxi Wu Xintao Du Wenxin 《Structural chemistry》2004,15(3):207-210
A new Cu(II)PMIDA compound [Cu(H2PMIDA)(phen)] 3H2O (1) (H4PMIDA = H2O3PCH2N (CH2CO2H)2,phen = 1,10-phenanthroline) has been successfully synthesized and structurally characterized. In complex 1, Cu (II) is six coordinated by chelation in a tetradentate fashion by a PMIDA ligand and by two N atoms of a phen ligand. Every phen–Cu(II)–PMIDA group connects with each other via a hydrogen bond and the edge-to-face -stacking interaction. Complex 1 crystallized in triclinic P-1 with cell dimensions of a = 7.5817(6) Å, b = 10.6980(8) Å, c = 13.1852(10) Å, =82.350(2)°, = 84.151(2)°, =78.4250(2), V= 1035.25(14) Å3, Z = 2, Dc = 1.677 Mg/m3. 相似文献
9.
Brant J. Chapman Graham B. Jones William T. Pennington 《Journal of chemical crystallography》1999,29(4):383-389
(—)-8-Phenylmenthol was prepared and converted to the corresponding tricarbonyl (6-arene) chromium(0) complex. Derivitization as the acrylate ester (1) and subsequent X-ray analysis revealed a 1:1 mix of s-cis and s-trans acrylate in the unit cell, and geometric proximity to support a through-space stacking interaction in the case of the s-trans isomer. The dihedral angle between the best planes through the chromium-bound aryl ring and the acrylate group is 19.9° for the s-trans isomer and 34.4° for the s-cis isomer. Crystal data for (1): C22H26O5Cr, monoclinic, P21 (No. 4), a = 10.269(1), b = 10.482(1), c = 19.787(2), = 95.85(1), Z = 4, and D
calc = 1.32 g cm–3. 相似文献
10.
Randall K. Reigle Dominick J. Casadonte Jr. Simon G. Bott 《Journal of chemical crystallography》1994,24(11):753-758
The synthesis and crystal structure of a bimetallic luminescent Cu(I) complex containing 1,4-bis(diphenylphosphinesulfido)butane and the -diimine 2,9-dimethyl-1,10-phenanthroline (dmp) is described. The coordination geometry about the Cu(I) center is pseudo-tetrahedral. Interplanar interactions between phenyl groups on the phosphine sulfide ligands and the phenanthroline exist which are indicative ofintramolecular -stacking, leading to compressed S–Cu–S bond angles. The complex displays emission from a single metal-centered charge-transfer state at 77 K in a 41 ethanol/methanol (v/v) glass. This is in contrast to the triphenylphosphine complex, which exhibits dual luminescence from a charge-transfer and an intraligand state at 77 K. Crystal data: triclinic,
,a=13.619(4) Å,b=13.673(2) Å,c=15.384(2) Å, =75.08(1)°, =80.35(2)°, =80.67(2)°. 相似文献