RESUMO
A novel pyromellitic diimide-extended pillar[6]arene was synthesized in two steps with moderate yield for the first time. It showed a symmetrical stretched hexagon structure and could form 1:2 complexes with polycyclic aromatic hydrocarbons in solution. Interestingly, a linear supramolecular array between complex 1@G42 and pyrene through π···π stacking interactions was also observed in the solid state.
RESUMO
Through a combinatorial screening of 35 possible phase-selective monopeptide-based organogelators readily made at low cost, we identified five of them with high gelling ability toward aprotic aromatic solvents in the powder form. The best of them (Fmoc-V-6) is able to instantly and phase-selectively gel benzene, toluene, and xylenes in the presence of water at room temperature at a gelator loading of 6% w/v. This enables the gelled aromatics to be separated by filtration and both aromatics and the gelling material to be recycled by distillation. We also identified Fmoc-I-16 as the best gelator for benzyl alcohol, and the corresponding organogel efficiently removes toxic dye molecules by 82-99% from their highly concentrated aqueous solutions. These efficient removals of toxic organic solvents and dyes from water suggest their promising applications in remediating contaminated water resources.
RESUMO
A series of novel 2,3- or 2,5-dispirooxindole-piperazine ring systems were efficiently constructed through the acid-promoted self-1,3-dipolar [3+3] cyclizations of azomethine ylides derived from isatin with various primary or cyclic secondary amines. Interestingly, the regioselectivity of this self-[3+3] cyclization could be effectively tuned by varying the structural features of substrates. The unprecedented 2,5-dispirooxindole-piperazine skeleton was achieved in good diastereoselectivity by employing 1,2,3,4-tetrahydroisoquinoline, while using pyrrolidine or glycine methyl ester furnished the 2,3-dispirooxindole-piperazine scaffold in excellent diastereoselectivity (only a single isomer formed).
RESUMO
Metal complexes, particularly copper(II) complexes, are often used as anticancer drugs due to their ability to generate reactive oxygen species (ROS) in cells. Four copper(II) complexes have been designed based on ligands for triplet pyridine derivatives (complexes 1-4), and their structures have been determined using X-ray single crystal analysis. The interactions of these complexes with calf thymus DNA (CT-DNA) have been investigated using various techniques, including UV-vis absorption, viscosity measurements, and circular dichroism spectroscopy. The results indicate that complexes 1-4 strongly interact with DNA through partial intercalations. Further investigation using agarose gel electrophoresis shows that all four complexes can cleave pBR322 DNA in the presence of ascorbic acid as a reducing agent, and the DNA cleavage mechanism is through the generation of singlet oxygen (1O2). In vitro anticancer activities of these complexes have been evaluated using A549, MDA-MB-231, HeLa, and HepG2 cells. The calculated IC50 values indicate significant efficacy against cancer cells. Additionally, AO/EB staining assays reveal that these complexes induce cell apoptosis in HeLa cell line.
Assuntos
Antineoplásicos , Complexos de Coordenação , Humanos , Células HeLa , Cobre/química , Ligantes , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Antineoplásicos/farmacologia , Antineoplásicos/química , DNA/química , Clivagem do DNA , Cristalografia por Raios XRESUMO
In the title compound, {[NiWO(4)(C(16)H(36)N(4))]·4H(2)O}(n), the Ni(II) ion lies on an inversion center and is octahedrally coordinated by four N atoms of the tetradentate macrocyclic 5,5,7,12,12,14-hexa-methyl-1,4,8,11-tetra-aza-cyclo-tetra-decane (L) ligand in the equatorial plane and two O atoms of [WO(4)](2-) anions in axial positions. Each [WO(4)](2-) anion bridges two adjacent [NiL](2+) cations, forming a chain along [001]. The chains are further connected via N-Hâ¯O, O-Hâ¯O and C-Hâ¯O hydrogen-bonding inter-actions, generating a three-dimensional structure.
RESUMO
Liquid molecules are difficult to crystallize, and their structures and absolute configurations cannot be directly determined by X-ray crystallography. We herein report the rapid cocrystallization of tetraaryladamantanes with liquid molecules. The structure of the liquid small molecules can be obtained by determining the crystal structure of the cocrystallized compound. The absolute configuration of chiral molecules can also be assigned, which cannot be accomplished by other methods such as nuclear magnetic resonance. In this paper, liquid compounds such as phenylethanol and phenylpropanol derivatives were selected. 1,3,5,7-Tetrakis(2,4-diethoxyphenyl)adamantane (TEO) powder was heated and dissolved in liquid molecules and allowed to stand overnight to undergo cocrystallization. The results show that the single-crystal structures and the absolute configurations of 16 liquid molecules were determined by cocrystallization, and the homochiral natures of chiral compounds were confirmed by solid circular dichroism spectral measurements.
RESUMO
In the title salt, [NaZn(2)(CH(3)COO)(2)(ClO(4))(2)(C(16)H(36)N(4))(2)]ClO(4), the macrocyclic ligand binds to the Zn(2+) cations through their four amino N atoms; the Zn(2+) cations are also each covalently bonded to an acetate ion. For one zinc atom, the acetate group is monodentate, and the geometry is a distorted ZnN(4)O trigonal bipyramid; for the other, the acetate group is anisobidentate and the geometry is a distorted ZnN(4)O(2) octa-hedron. The two macrocycle-zinc acetate units are bridged through a diperchloratosodium unit. In the crystal, the complex cations and uncoordinated perchlorate anions are linked by N-Hâ¯O hydrogen bonds.
RESUMO
In the title salt, [Ni(C(7)H(6)NO(2))(C(16)H(36)N(4))]ClO(4)·H(2)O, the Ni(II) cation is O,O'-chelated by the benzoate anion and N,N',N'',N'''-chelated by the macrocycle ligand, confering a distorted octa-hedral geometry on the metal atom. The complex cations, perchlorate anions and uncoordinated water mol-ecules are linked by N-Hâ¯O and O-Hâ¯O hydrogen bonds into a three-dimensional network. The perchlorate ion is disordered over two positions in a 0.554â (8):0.446â (8) ratio.
RESUMO
In the crystal structure of the title salt, [Ni(C(3)H(3)O(4))(C(16)H(36)N(4))]ClO(4)·CH(3)CN, the macrocycle folds around the Ni(II) atom, which is also chelated by the carboxyl-ate monoanion. The geometry is a distorted NiN(4)O(2) octa-hedron. The formula units are connected by N-Hâ¯O hydrogen bonds into centrosymmetric dimers. Further N-Hâ¯O and O-Hâ¯O hydrogen bonds link the complex mol-ecules and the perchlorate ions.
RESUMO
The 4-carboxy-imidazole-5-carboxyl-ate(2-) dianion in the title compound, [Ni(C(5)H(2)N(2)O(4))(C(16)H(36)N(4))]·H(2)O, N,O'-chelates to the Ni(II) atom, which shows an octa-hedral coordination. The macrocycle folds itself around the metal atom and binds to it through four secondary nitrogen atoms; adjacent molecules are linked by N-Hâ¯O hydrogen bonds into a linear chain. The water molecule is disordered over two positions.
RESUMO
Both mol-ecules of the title compound, [Ni(C(2)O(4))(C(16)H(36)N(4))]·C(2)H(2)O(4), are located on a crystallographic twofold rotation axis. The Ni(II) atom shows a distorted octa-hedral geometry. The crystal packing is stabilized by N-Hâ¯O and O-Hâ¯O hydrogen bonds.
RESUMO
The title compound, [Ni(C(8)H(5)O(4))(C(16)H(36)N(4))]ClO(4)·H(2)O, has the Ni(II) atom in a distorted octa-hedral geometry, surrounded by coordination by four N atoms of the 5,5,7,12,12,14-hexa-methyl-1,4,8,11-tetra-azacyclo-tetra-decane ligand in a folded configuration, and two carboxyl-ate O atoms of the 2-carboxy-benzoate ligand in cis positions. The complex cation, the disordered perchlorate anion [occupancies 0.639â (8):0.361â (8)] and uncoordinated water mol-ecules engage in N-Hâ¯O and O-Hâ¯O hydrogen bonding, forming a layer structure parallel to (010).
RESUMO
In the crystal structure of the title dinuclear compound, [Ni(2)(C(4)H(4)O(5))(C(16)H(36)N(4))(2)](ClO(4))(2)·H(2)O, the bridg-ing di-car-box-yl-ate dianion O,O'-chelates to two Ni atoms, both of which are also chelated by the N-macrocylic ligand. The Ni atoms exhibit a distorted octa-hedral coordination. N-Hâ¯O and O-Hâ¯O hydrogen bonds link the cations and the uncoordinated water mol-ecules into a layer structure; the perchlorate anions occupy the space between adjacent layers, and are only weakly linked to the layers. One of the perchlorate anions is disordered over two sets of sites in a 3:2 ratio.
RESUMO
The Ni atom in the title salt, [Ni(C(7)H(5)O(2))(C(16)H(36)N(4))]ClO(4)·H(2)O, is in a six-coordinate octa-hedral geometry. The metal atom is chelated by the carboxyl-ate group, and the macrocyclic ligand adopts a folded configuration. The cation, anion and water mol-ecules engage in hydrogen bonding to form a layer structure.
RESUMO
In the title compound, [Ag(2)(C(6)H(6)NO(3)S)(2)(C(10)H(8)N(2))(2)](n), the Ag(I) atom is four-coordinated by two N atoms from two symmetry-related 4,4'-bipyridine (bipy) and two O atoms from two independent 4-amino-benzene-sulfonate (ABS) ligands. The two inter-chain Ag(I) atoms are bridged by two independent ABS ligands through weak Ag-O bonds and Agâ¯Ag attractions, forming a ladder-like chain coordination polymer [Ag(2)(ABS)(2)(bipy)(2)](n) parallel to [001], which is further linked to generate a two-dimensional structure via N-Hâ¯O hydrogen-bonding inter-actions.
RESUMO
In the title compound, [Ni(C(7)H(5)O(2))(C(16)H(36)N(4))]ClO(4)·C(7)H(6)O(2), the Ni atom displays a distorted octa-hedral coordination geometry with four N atoms of the ligand rac-5,5,7,12,12,14-hexa-methyl-1,4,8,11-tetra-azacyclo-tetra-decane (L) in a folded configuration and two benzoate (bz) O atoms. The [Ni(rac-L)(bz)](+) complex cation, perchlorate anion and benzoic acid mol-ecules engage in hydrogen bonding, with Nâ¯O distances between 2.970â (3) and 3.123â (3)â Å and an Oâ¯O distance of 2.691â (3)â Å.
RESUMO
The title compound, C(30)H(50)O(3), which was isolated from a marine endophytic fungus, is a new friedelan derivative. The mol-ecule contains five six-membered rings, which exhibit boat (ring A), distorted boat (ring B) and chair (rings C-E) conformations. The crystal structure is stabilized by inter-molecular O-Hâ¯O hydrogen bonds, which link neighbouring mol-ecules into 12-membered rings.
RESUMO
The highly diastereoselective intramolecular [3+2] annulation via the ring-opening of a cyclopropane diester derivative has been developed to construct a dihydroquinolinone scaffold. A series of tricyclic dihydroquinolinones bearing one or two all-carbon quaternary stereogenic centers were obtained in good yields and excellent diastereoselectivities (up to 20 : 1 dr). Moreover, the amide-linking mode shows obviously beneficial effects on the ring-opening of cyclopropane.
RESUMO
The enantiopure agents d- and l-leucine, selectively bind RR and SS enantiomers from a racemate [Ni(alpha-rac-L)](2+) to give {[Ni(RR-L)(d-HLeu)](ClO(4))(2)}(n) (Delta-) and {[Ni(SS-L)(l-HLeu)](ClO(4))(2)}(n) (Lambda-), respectively, and leave the corresponding uninteracted SS and RR enantiomers of [Ni(alpha-SS-L)](ClO(4))(2) (S-) and [Ni(alpha-RR-L)](ClO(4))(2) (R-). Occasionally, a few crystals of {[Ni(RR-L)(l-HLeu)](ClO(4))(2)}(n) (Delta-) and {[Ni(SS-L)(d-HLeu)](ClO(4))(2)}(n) (Lambda-) were found to have accreted with the crystals of Lambda-/R-, and Delta-/S-, respectively (the yields are less than 2%). The results of X-ray crystal structural analysis reveal that Delta- and Lambda-, S- and R-, and Delta- and Lambda- are enantiomers, in which Delta- and Delta- possess 1D right-handed helical chains, while Lambda- and Lambda- exhibit a motif of 1D left-handed helical chains. The results of DFT calculations reveal that the single-point energies of [Ni(RR-L)(d-HLeu)](2+)/[Ni(SS-L)(l-HLeu)](2+) in Delta-/Lambda- are 582 kJ mol(-1) lower than those of [Ni(RR-L)(l-HLeu)](2+)/[Ni(SS-L)(d-HLeu)](2+) in Delta-/Lambda-, demonstrating the favorable stereo-coordination environments of [Ni(alpha-RR-L)](2+) and [Ni(alpha-SS-L)](2+) towards d and l-HLeu, respectively.
Assuntos
Compostos Macrocíclicos/química , Dicroísmo Circular , Complexos de Coordenação/química , Cristalografia por Raios X , Ligantes , Conformação Molecular , Níquel/química , EstereoisomerismoRESUMO
The reactions of four-coordinated transition metal macrocyclic complexes [ML](ClO(4))(2) (L = 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane, M = Ni, Cu) with NH4VO3 under different conditions gave four coordination polymers of {[(CuL)(0.5)(H2L)(1.5)][H2V10O2)] x 6H(2)O}(n) (1x6H(2)O), {[NiL](3)[V16O38(H2O)] x 6H(2)O}(n) (2 x 6H(2)O), {[NiL][VO(3)](2) x 0.33H2O}(n) (3.0.33H(2)O), and {[CuL][VO(3)](2) x 0.33H(2)O}(n) (4 x 0.33H2O). Single crystal X-ray diffraction analyses reveal that four diverse vanadium polyoxoanions, [H2V1oO28)(4-) cluster, [V16O38(H2O)](6-) cage, [V6O18](6-) ring, and [VO(3)](n)(n-) chain, were obtained from the same reactant NH(4)VO(3) under different conditions. In 1, the cluster anion [H2V10O28](4-) alternately bridges [CuL]2+/[H2L]2+ to form a one-dimensional chain, and the [V16O38(H2O)](6-) cage in 2 links three [NiL]2+ into a two-dimensional sheet. Compounds 3 and 4 show three-dimensional structures, which are constructed by the connections of hexanuclear [V6O18](6-) rings with [NiL]2+ in 3 and [VO3](n)(n-) chains with [CuL]2+ in 4, respectively, generating one-dimensional channels occupied by guest water molecules.