ROLE OF WEAK INTERACTIONS IN THE STRUCTURE OF 3-(α,α′-DIBROMOMETHYL)BENZYL 1-4 BENZOTRIAZOLE (DBT)

Author(s):  
M. Kuppayee ◽  
S. M. Malathy Sony ◽  
M. N. Ponnuswamy ◽  
V. Murali ◽  
P. Rajakumar
Keyword(s):  
Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 13
Author(s):  
Mohd. Muddassir ◽  
Abdullah Alarifi ◽  
Mohd. Afzal

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.


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

2020 ◽  
Vol 117 (37) ◽  
pp. 22690-22697 ◽  
Author(s):  
M. R. W. Scheepers ◽  
L. J. van IJzendoorn ◽  
M. W. J. Prins

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.


Author(s):  
Kevin S. McCann

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.


2020 ◽  
Vol 501 ◽  
pp. 119243 ◽  
Author(s):  
Ghodrat Mahmoudi ◽  
Payam Hayati ◽  
Khosro Mohammadi ◽  
Ardavan Masoudiasl ◽  
Joel T. Mague ◽  
...  

Synlett ◽  
2020 ◽  
Vol 31 (13) ◽  
pp. 1259-1267
Author(s):  
Tadashi Mori

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


2016 ◽  
Vol 145 (14) ◽  
pp. 144901 ◽  
Author(s):  
Daria Galimberti ◽  
Alberto Milani ◽  
Lorenzo Maschio ◽  
Chiara Castiglioni

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):  

RSC Advances ◽  
2016 ◽  
Vol 6 (78) ◽  
pp. 74506-74509 ◽  
Author(s):  
Y. Akune ◽  
R. Hirosawa ◽  
H. Takahashi ◽  
M. Shiro ◽  
S. Matsumoto

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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