Equifinality versus evolutionary fragility: the role of collective weak interactions

2002 ◽  
Author(s):  
L.G. Volkert ◽  
M. Conrad
Keyword(s):  
Weak Interactions

scholarly journals A New Piano-Stool Ruthenium(II) P-Cymene-Based Complex: Crystallographic, Hirshfeld Surface, DFT, and Luminescent Studies

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 13
Author(s):  
Mohd. Muddassir ◽  
Abdullah Alarifi ◽  
Mohd. Afzal
Keyword(s):  
Density Functional ◽  
Weak Interactions ◽  
Energy Levels ◽  
Hirshfeld Surface ◽  
Binding Energies ◽  
Orbital Energy ◽  
Aminosalicylic Acid ◽  
Full Characterization

A new complex (Ru(η6-p-cymene)(5-ASA)Cl2) (1) where 5-ASA is 5-aminosalicylic acid has been prepared by reacting the ruthenium arene precursors ((η6-arene)Ru(μ-Cl)Cl)2, with the 5-ASA ligands in a 1:1 ratio. Full characterization of complex 1 was accomplished by elemental analysis, IR, and TGA following the structure obtained from a single-crystal X-ray pattern. The structural analysis revealed that complex 1 shows a “piano-stool” geometry with Ru-C (2.160(5)- 2.208(5)Å), Ru-N (2.159(4) Å) distances, which is similar to equivalents sister complex. Density functional theory (DFT) was used to calculate the significant molecular orbital energy levels, binding energies, bond angles, bond lengths, and spectral data (FTIR, NMR, and UV–VIS) of complex 1, consistent with the experimental results. The IR and UV–VIS spectra of complex 1 were computed using all of the methods and choose the most appropriate way to discuss. Hirshfeld surface analysis was also executed to understand the role of weak interactions such as H⋯H, C⋯H, C-H⋯π, and vdW interactions, which play a significant role in the crystal environment’s stability. Moreover, the luminescence results at room temperature show that complex 1 gives a more intense emission band positioned at 465 nm upon excitation at 330 nm makes it a suitable candidate for the building of photoluminescent material.

Role of the Weak Interactions during the 2,4,6-Trinitrophenol Detecting Process of a Fluorescein-Based Sensor

2021 ◽  
Vol 125 (36) ◽  
pp. 7867-7875
Author(s):  
Lei Liu ◽  
Bingqing Sun ◽  
Ran Ding ◽  
Yueyuan Mao
Keyword(s):  
Weak Interactions

scholarly journals Multivalent weak interactions enhance selectivity of interparticle binding

2020 ◽  
Vol 117 (37) ◽  
pp. 22690-22697 ◽  
Author(s):  
M. R. W. Scheepers ◽  
L. J. van IJzendoorn ◽  
M. W. J. Prins
Keyword(s):  
Targeted Drug Delivery ◽  
Colloidal Particles ◽  
High Selectivity ◽  
Weak Interactions ◽  
Theoretical Work ◽  
Coated Particles ◽  
Receptor Interactions ◽  
Two Factors ◽  
Experimental Findings

Targeted drug delivery critically depends on the binding selectivity of cargo-transporting colloidal particles. Extensive theoretical work has shown that two factors are necessary to achieve high selectivity for a threshold receptor density: multivalency and weak interactions. Here, we study a model system of DNA-coated particles with multivalent and weak interactions that mimics ligand–receptor interactions between particles and cells. Using an optomagnetic cluster experiment, particle aggregation rates are measured as a function of ligand and receptor densities. The measured aggregation rates show that the binding becomes more selective for shorter DNA ligand–receptor pairs, proving that multivalent weak interactions lead to enhanced selectivity in interparticle binding. Simulations confirm the experimental findings and show the role of ligand–receptor dissociation in the selectivity of the weak multivalent binding.

More Modules

2011 ◽  
Author(s):  
Kevin S. McCann
Keyword(s):  
Population Dynamics ◽  
Food Webs ◽  
Empirical Evidence ◽  
Intraguild Predation ◽  
Weak Interactions ◽  
Apparent Competition ◽  
Trade Offs ◽  
Variable Population ◽  
The Stability

This chapter considers four-species modules and the role of generalism (effectively a three-species module with a consumer feeding on two resources). It first examines how generalists affect the dynamics of food webs by focusing on a set of modules that contrast generalist consumer dynamics relative to the specialist case. It then discusses organismal trade-offs that play a role in governing the diamond food web module and the intraguild predation module, arguing that such tradeoffs influence the flux of matter, the organization of interaction strengths, and ultimately the stability of communities. The chapter also reviews empirical evidence showing that apparent competition and the diamond module with and without intraguild predation are ubiquitous, and that weak interactions in simple modules seem to promote less variable population dynamics.

The role of weak interactions in the crystal packing of two novel 1D Hg(II) coordination polymers and investigation for preparation of their rod and spherical structures

2020 ◽  
Vol 501 ◽  
pp. 119243 ◽  
Author(s):  
Ghodrat Mahmoudi ◽  
Payam Hayati ◽  
Khosro Mohammadi ◽  
Ardavan Masoudiasl ◽  
Joel T. Mague ◽  
...  
Keyword(s):  
Coordination Polymers ◽  
Crystal Packing ◽  
Weak Interactions ◽  
Spherical Structures

Relevance of the Entropy Factor in Stereoselectivity Control of Asymmetric Photoreactions

Synlett ◽  
2020 ◽  
Vol 31 (13) ◽  
pp. 1259-1267
Author(s):  
Tadashi Mori
Keyword(s):  
Activation Energy ◽  
Excited States ◽  
Weak Interactions ◽  
Supramolecular Interactions ◽  
Thermal Reactions ◽  
Thermodynamics And Kinetics ◽  
Control Concept ◽  
Entropy Factor ◽  
Fine Tune

Entropy as well as enthalpy factors play substantial roles in various chemical phenomena such as equilibrium and reactions. However, the entropy factors are frequently underestimated in most instances, particularly in synthetic chemistry. In reality, the entropy factor can be in competition with the enthalpy factor or can even be decisive in determining the overall free or activation energy change upon molecular interaction and chemical transformation, particularly where weak interactions in ground and/or excited states are significant. In this account, we overview the importance of the entropy factor in various chemical phenomena in both thermodynamics and kinetics and in the ground and excited states. It is immediately apparent that many diastereo- and enantioselective photoreactions are entropy-controlled. Recent advances on the entropy-control concept in asymmetric photoreactions are further discussed. Understanding the entropy-control concept will pave the way to improve, fine-tune, and even invert the chemo- and stereoselectivity of relevant chemical phenomena.1 Introduction2 Role of Entropy in Supramolecular Interactions3 Selected Examples of Entropy-Driven Thermal Reactions4 Classical Examples of Entropy Control in Photoreactions5 Entropy-Driven Asymmetric Photoreactions6 Advances in Entropy Control7 Perspective

scholarly journals Intermolecular modulation of IR intensities in the solid state. The role of weak interactions in polyethylene crystal: A computational DFT study

2016 ◽  
Vol 145 (14) ◽  
pp. 144901 ◽  
Author(s):  
Daria Galimberti ◽  
Alberto Milani ◽  
Lorenzo Maschio ◽  
Chiara Castiglioni
Keyword(s):  
Solid State ◽  
Weak Interactions ◽  
Dft Study ◽  
Ir Intensities

ChemInform Abstract: Role of Fluorine in Weak Interactions in Co-crystals

ChemInform ◽  
2012 ◽  
Vol 43 (15) ◽  
pp. no-no
Author(s):  
Seetha Lekshmi Sunil ◽  
Susanta K. Nayak ◽  
Venkatesha R. Hathwar ◽  
Deepak Chopra ◽  
Tayur N. Guru Row
Keyword(s):  
Weak Interactions

scholarly journals Role of flexible bulky groups and weak interactions involving halogens in the vapoluminescence of a metal-free dye

RSC Advances ◽  
2016 ◽  
Vol 6 (78) ◽  
pp. 74506-74509 ◽  
Author(s):  
Y. Akune ◽  
R. Hirosawa ◽  
H. Takahashi ◽  
M. Shiro ◽  
S. Matsumoto
Keyword(s):  
Weak Interactions ◽  
Molecular Flexibility ◽  
Metal Free

The vapoluminescence of a 2,5-diamino-3,6-dicyanopyrazine dye was correlated with molecular flexibility of bulky substituents and weak interactions involving halogens.

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