scholarly journals Rotaxane PtII-complexes: mechanical bonding for chemically robust luminophores and stimuli responsive behaviour

2020 ◽  
Vol 11 (7) ◽  
pp. 1839-1847 ◽  
Author(s):  
Zhihui Zhang ◽  
Graham J. Tizzard ◽  
J. A. Gareth Williams ◽  
Stephen M. Goldup
Keyword(s):  
Metal Ion ◽  
Stimuli Responsive ◽  
Coordination Environment ◽  
Mechanical Bond ◽  
Mechanical Bonding

We report an approach to interlocked PtII luminophores in which the mechanical bond stabilises the coordination environment of the embedded metal ion.

scholarly journals Recent Advances in Stimuli-Responsive Photofunctional Materials Based on Accommodation of Chromophore into Layered Double Hydroxide Nanogallery

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Wu Li ◽  
Dongpeng Yan ◽  
Rui Gao ◽  
Jun Lu ◽  
Min Wei ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Metal Ion ◽  
Recent Progress ◽  
Stimuli Responsive ◽  
Responsive Materials ◽  
Chemical Factors ◽  
Host Matrices ◽  
Double Hydroxide ◽  
Double Hydroxides ◽  
Further Development

The assembly of photofunctional molecules into host matrices has become an important strategy to achieve tunable fluorescence and to develop intelligent materials. The stimuli-responsive photofunctional materials based on chromophores-assembled layered double hydroxides (LDHs) have received much attention from both academic and industry fields as a result of their advantages, such as high photo/thermal stability, easy processing, and well reversibility, which can construct new types of smart luminescent nanomaterials (e.g., ultrathin film and nanocomposite) for sensor and switch applications. In this paper, external environmental stimuli have mainly involved physical (such as temperature, pressure, light, and electricity) and chemical factors (such as pH and metal ion); recent progress on the LDH-based organic-inorganic stimuli-responsive materials has been summarized. Moreover, perspectives on further development of these materials are also discussed.

scholarly journals Enhancing the selectivity of prolinamide organocatalysts using the mechanical bond in [2]rotaxanes

2020 ◽  
Vol 11 (14) ◽  
pp. 3629-3635 ◽  
Author(s):  
María Calles ◽  
Julio Puigcerver ◽  
Diego A. Alonso ◽  
Mateo Alajarin ◽  
Alberto Martinez-Cuezva ◽  
...  
Keyword(s):  
Mechanical Bond ◽  
Mechanical Bonding

The mechanical bonding and the cofactor assembly in interlocked prolinamide-based organocatalysts upgrade enamine-type transformations by increasing their yields and enantio- and chemo-selectivities.

A conformationally switchable fluorescent oligophenol foldamer for selective sensing of copper(ii) ions

RSC Advances ◽  
2014 ◽  
Vol 4 (97) ◽  
pp. 54469-54473 ◽  
Author(s):  
Jiaqiang Liu ◽  
Chang Sun ◽  
Wenliang Ma ◽  
Yu-Jing Lu ◽  
Lin Yu ◽  
...  
Keyword(s):  
Fluorescence Quenching ◽  
Metal Ion ◽  
Stimuli Responsive

A stimuli-responsive hexameric oligophenol host undergoes amine-induced co-operative folding and fluorescence quenching, enabling easy classification of the bound metal ion guests as well as selective sensing of Cu2+ ions.

Structural Characterization of Encapsulation Reactions Based on the Tris(ethane-1,2-diamine)cobalt(III) Ion

1993 ◽  
Vol 46 (10) ◽  
pp. 1485 ◽  
Author(s):  
IJ Clark ◽  
RJ Geue ◽  
LM Engelhardt ◽  
JM Harrowfield ◽  
AM Sargeson ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Metal Ion ◽  
Bond Angle ◽  
Orthorhombic Space Group ◽  
Molecular Rearrangement ◽  
Coordination Environment ◽  
Catalysed Reaction ◽  
Structural And Electronic Properties ◽  
Coordination Spheres

On the basis of structural comparisons involving intermediates and side products of encapsulation reactions as well as several cage complexes, the efficiency of the base- catalysed reaction between formaldehyde, nitromethane and [Co(en)3]3+ (en = ethane-1,2-diamine) to give [Co((NO2)2sar)]3+ appears to be explicable in terms of the 'interlocking' of constituent parts without appreciable concomitant bond length or bond angle distortions. Thus, the structures of the podand ligand complexes Λ-[Co(NO2sen)]Cl3.2H2O [orthorhombic, space group P 212121, a 18.755(6), b 11.598(4), c 9.164(3) Ǻ; R 0.038 for No 1735 'observed' reflections] and Δ,Λ-[Co(Nt-Me,NO2sen)]Cl3.4H2O [monoclinic, P21/n, a 18.613(5), b 9.301(3), c 13.779(4) Ǻ, β 107.10(2)°; R 0.051 for No 26441 show very close configurational and conformational similarities to those of the cage complexes Δ,Λ-[Co(NO2azasar)]Cl3.3H2O [monoclinic, P 21/c, a 9.339(3), b 15.479(9), c 17.360(7)Ǻ, β 114.15(3)°; R 0.048 for No 2612], Δ,Λ-[Co((NO2)2sar)]Cl3.2H2O [triclinic, Pī , a 13.592(3), b 10.024(3), c 9.772(3)Ǻ, α 62.89(2),β 82.96(3), γ 85.15(2)°; R 0.045 for No 5646] and Δ,Λ-[Co((OH)2sar)]Cl3.3H2O [monoclinic, P21/c, a 15.97(1), b 8.758(4), c 16.760(4)Ǻ, β 98.72(4)°; R 0.052 for No 2400], as well as to published structures of [Co(en)3]3+, [Co(tame)2]3+ [tame = 1,1,1-tris- ( aminomethyl )ethane = ethylidynetris ( methanamine )] and other cage complexes. Some of these similarities may be associated with common hydrogen-bonding patterns in the solids resulting from anion ' chelation' by adjacent NH moieties in the metal ion coordination spheres. Necessary caution in relating structural and electronic properties is implied by the structure determination for Δ,Λ [Co(Cl,ClCH2absar)](NO3)3 [monoclinic, P 21/c, a 14.750(6), b 9.264(3), c 17.959(7) Ǻ, β 95.80(3)°; R 0.061 for No 1431], one of the products of molecular rearrangement following nitrosation of [Co((NH2)2sar)]3+. Despite marked electronic spectral and electrochemical differences with its parent complex, [Co(Cl,ClCH2absar)](NO3)3 contains cobalt(III) in a coordination environment which remains similar to those in more symmetrical cage complexes.

scholarly journals Bacterial Succinoglycans: Structure, Physical Properties, and Applications

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 276
Author(s):  
Jae-pil Jeong ◽  
Yohan Kim ◽  
Yiluo Hu ◽  
Seunho Jung
Keyword(s):  
Drug Delivery ◽  
Physical Properties ◽  
Metal Ion ◽  
Structural Characteristics ◽  
Culture Conditions ◽  
Medium Composition ◽  
Stimuli Responsive ◽  
Food Industries ◽  
Acetyl Group ◽  
Functional Biomaterials

Succinoglycan is a type of bacterial anionic exopolysaccharide produced from Rhizobium, Agrobacterium, and other soil bacteria. The exact structure of succinoglycan depends in part on the type of bacterial strain, and the final production yield also depends on the medium composition, culture conditions, and genotype of each strain. Various bacterial polysaccharides, such as cellulose, xanthan, gellan, and pullulan, that can be mass-produced for biotechnology are being actively studied. However, in the case of succinoglycan, a bacterial polysaccharide, relatively few reports on production strains or chemical and structural characteristics have been published. Physical properties of succinoglycan, a non-Newtonian and shear thinning fluid, have been reported according to the ratio of substituents (pyruvyl, succinyl, acetyl group), molecular weight (Mw), and measurement conditions (concentration, temperature, pH, metal ion, etc.). Due to its unique rheological properties, succinoglycan has been mainly used as a thickener and emulsifier in the cosmetic and food industries. However, in recent reports, succinoglycan and its derivatives have been used as functional biomaterials, e.g., in stimuli-responsive drug delivery systems, therapeutics, and cell culture scaffolds. This suggests a new and expanded application of succinoglycan as promising biomaterials in biomedical fields, such as tissue engineering, regenerative medicine, and pharmaceuticals using drug delivery.

scholarly journals The first phosphoramide–mercury(II) complex with a Cl2Hg–OP[N(C)(C)]3segment

2016 ◽  
Vol 72 (3) ◽  
pp. 230-233 ◽  
Author(s):  
Anahid Saneei ◽  
Mehrdad Pourayoubi ◽  
Aurelien Crochet ◽  
Katharina M. Fromm
Keyword(s):  
Coordination Number ◽  
Lewis Acid ◽  
Metal Ion ◽  
Coordination Mode ◽  
Complex Molecule ◽  
Relativistic Effects ◽  
Asymmetric Unit ◽  
Coordination Environment ◽  
Bond Valence Sum ◽  
Linear Coordination

Mercury(II) exhibits a strong preference for linear coordination which has been attributed to relativistic effects splitting the 6porbitals and promotingsphybridization. If the two ligands attached to the mercury(II) ion are weak donors, the metal ion can act as a good Lewis acid and expand its coordination number. Moreover, mercury has a special affinity for softer bases, such as S and N atoms, and has much less affinity for hard bases, such as those including an O atom. The asymmetric unit of dichlorido[tris(piperidin-1-yl)phosphane oxide-κO]mercury(II)–dichloridomercury(II) (2/1), [HgCl2{(C5H10N)3PO}]2·[HgCl2], is composed of one HgCl2{(C5H10N)3PO} complex and one half of a discrete HgCl2entity located on an inversion centre. The coordination environment around the HgIIcentre in the complex component is a distorted T-shape. Bond-valence-sum calculations confirm the three-coordination mode of the HgIIatom of the complex molecule. The noncovalent nature of the Hg...Cl and Hg...O interactions in the structure are discussed.

scholarly journals Stimuli-responsive nucleic acid-functionalized metal–organic framework nanoparticles using pH- and metal-ion-dependent DNAzymes as locks

2017 ◽  
Vol 8 (8) ◽  
pp. 5769-5780 ◽  
Author(s):  
Wei-Hai Chen ◽  
Xu Yu ◽  
Alessandro Cecconello ◽  
Yang Sung Sohn ◽  
Rachel Nechushtai ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Metal Ion ◽  
Metal Organic Framework ◽  
Stimuli Responsive ◽  
Metal Organic ◽  
Organic Framework

Drug-loaded DNA-capped metal–organic framework nanoparticles are unlocked by pH or Mg2+ ions/ATP triggers, resulting in the release of the loads.

scholarly journals Synthesis, Crystal Structure, and Antimicrobial Properties of a Novel 1-D Cobalt Coordination Polymer with Dicyanamide and 2-Aminopyridine

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Amah Colette Benedicta Yuoh ◽  
Moise Ondoh Agwara ◽  
Divine Mbom Yufanyi ◽  
Mariam Aseng Conde ◽  
Rajamony Jagan ◽  
...  
Keyword(s):  
Coordination Polymer ◽  
Metal Ion ◽  
Antimicrobial Properties ◽  
X Ray Diffraction ◽  
Coordination Environment ◽  
One Dimensional ◽  
Distorted Octahedral ◽  
Elemental Analyses ◽  
Cobalt Coordination ◽  
Distorted Octahedral Coordination Environment

A novel one-dimensional coordination polymer bis(2-aminopyridine)-μ-bis(dicyanamido) cobaltate(II) has been synthesized and characterized by elemental analyses and infrared and ultraviolet visible spectroscopies and the structure has been determined by single crystal X-ray diffraction. Co(II) ion in the complex is coordinated to two axial 2-aminopyridine ligands through the pyridine N-atom and four equatorial dicyanamide ligands to give a CoN6 slightly distorted octahedral coordination environment around the metal ion. The amino N-atom forms intrachain hydrogen bonds. Antimicrobial screening of the complex against eight pathogenic microorganisms (four bacteria and four fungi) isolated from humans, indicates that the complex is moderately active.

A supramolecular polymer network gel with stimuli-responsiveness constructed by orthogonal metal ion coordination and pillar[5]arene-based host–guest recognition

2017 ◽  
Vol 8 (25) ◽  
pp. 3783-3787 ◽  
Author(s):  
Yuezhou Liu ◽  
Liqing Shangguan ◽  
Hu Wang ◽  
Danyu Xia ◽  
Bingbing Shi
Keyword(s):  
Metal Ion ◽  
Polymer Network ◽  
Supramolecular Polymer ◽  
Stimuli Responsive ◽  
External Stimuli

A novel external stimuli-responsive supramolecular polymer network gel was fabricated by orthogonal Ag-coordination and pillar[5]arene-based host–guest interactions.

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