Using the example of silatranes XSi(OCHCH)N (X = Me, H, F, Cl), , it was found that the effect of the dipole-bound (DB) electron on the cage intramolecular complexes does not fit into the standard views. Upon the transition from to the DB anions , the unusual shortening of the internuclear Si···N distance is always observed. For X = Cl, it is equal to 0.15 Å, which is a record length for all DB anions known from the literature. The formation of DB anions with the cage structure has principal features, controlled not only by the "critical" value of the dipole moment (μ > 2.5 D), but also by a geometric factor, such as the degree of pyramidality of the N(CH) moiety-the positive end of the molecular dipole of . It was a surprise that the effect of the substituent X on the extent of the structural rearrangement in the process → cannot be explained using the values of the electron detachment energy of or the initial strength of the coordination Si ← N bond in . The unique sensitivity of the silatrane geometry to the addition of an excess electron is governed by the rate of increase of their dipole moment with the shortening of the dative Si ← N contact. The conclusions drawn are supported by the high-accuracy CCSD and CCSD(T) calculations and the experimental (RET-PES) data. There is no real reason to doubt that the peculiarities of the formation of DB anions of can also be characteristic of many hundreds of their structural analogues XM(YCHCH)N (M = Si, Ge, Sn, Pb, Ti, Al, Cr, Fe, Ni...; Y = O, NR, CH, S), i.e., substituted 5-azabicyclo[3.3.3]undecans.
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http://dx.doi.org/10.1021/jacs.9b11694 | DOI Listing |
Langmuir
January 2025
School of Environment and Energy, South China University of Technology, Guangzhou 510006, People's Republic of China.
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Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, School of Geographical Sciences, Fujian Normal University, Fuzhou, China.
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January 2025
Department of Chemistry, School of Science, Xihua University, Chengdu, 610039, PR China.
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View Article and Find Full Text PDFChem Asian J
January 2025
Indian Institute of Science, Inorganic and Physical Chemistry, Indian Institute of Science, 560 012, Bangalore, INDIA.
Intracellular delivery of proteins is an important barrier in the development of strategies to deliver functional proteins and protein therapeutics into the cells to realize their full potential in biotechnology, biomedicine, cell-based therapies, and gene editing protein systems. Most of the intracellular protein delivery strategies involve the conjugation of cell penetrating peptides to enable and enhance the permeability of plasma membrane of mammalian cells to allow proteins to enter cytosol. Small molecules conjugations such as (p-methylphenyl) glycine, pyrenebutyrate and cysteines are used for the same purpose.
View Article and Find Full Text PDFPhysiol Plant
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Drought and nutrient-poor soils can increase the invasive potential of non-native species, further changing the ecosystems they invade. The high adaptability of these alien species, especially in their efficient use of resources, improves their resilience against abiotic stress. Here, we evaluated the response of the North American Quercus rubra L.
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