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Acids and Bases
Published in Michael B. Smith, A Q&A Approach to Organic Chemistry, 2020
A dative bond is a two-center, two-electron covalent bond in which both electrons come from the same atom. A dative bond is also called a coordinate covalent bond or simply a coordinate bond. Is it possible to view a Brønsted–Lowry acid in terms of the Lewis acid definition?
General Chemistry
Published in Steven L. Hoenig, Basic Chemical Concepts and Tables, 2019
A coordinate covalent bond, also referred to as a dative bond, is a bond in which both pairs of electrons are donated by one atom and are shared between the two, for example:
Column studies on the removal of chromium, lead, and Arsenic (Cr6+, Pb+2, and As3+) ions using graphene coated iron oxide (GCIO) as efficient nanoadsorbents
Published in Journal of Dispersion Science and Technology, 2023
Nidhi Khare, Jaya Bajpai, Anil Kumar Bajpai
In the direct method, metal ions are reduced from higher oxidation state (Cr6+, Pb4+, and As5+) to lower oxidation state (Cr3+, Pb2+, and As3+) through electron donating group (–NH2, –OH, and –CN, etc.) present on the surface of the adsorbent in acidic medium. Another mechanism II or indirect method, the reduction occurs in three steps which are given as follows In the first step negatively charged species of metal ions (Cr6+, Pb+2, and As3+) are generated in acidic environment which interact with positively charged adsorbent.In the next step metal ions are reduced to lower oxidation state.In the last step chemical (coordinate-covalent) bond formation occurs between generated species of metal ion with carbonyl containing group.
Molecularly imprinted hydrogel sensor for proteins
Published in Journal of Dispersion Science and Technology, 2023
Here, Wd is the weight of the dry hydrogel, and Ws is the weight of swollen hydrogel.[32]Furthermore, the consequences of cobalt during the swelling and sensing procedure inflated its importance. Figure 3a emphasizes the BSA and Co molar ratio sequels. By terminating the Co moles for BSA constant value, the swelling behavior of hydrogel increased in response to high Co moles. 1:15 is considered the most appealing condition for the swelling ratio. Swelling ratio difference pointing out the difference between the Ext-MIPH and MIPH with Co. From 1:1 to 1:9 difference in the swelling ratio was not so significant, but at 1:12, it shows a good increment. At 1:12 and 1:15, again, the difference was not so high because of the cobalt paramagnetic effect. Every single Co atom can expose to BSA for binding. BSA possesses 16 to 18 binding sites, but only one is presented for Co. Increase in Co molar ratio enhanced the binding sites available, ultimately increasing the sensing process by developing a coordinate covalent bond between BSA and Co.[33]
Experimental and theoretical investigation of pyrazinecarboxamide against mild steel corrosion
Published in Journal of Dispersion Science and Technology, 2023
Ayşen Keleşoğlu, Gökmen Sığırcık, Reşit Yıldız, İlyas Dehri
Electrostatic interaction along with the inhibitor compound and the surface of the metal is not strong, which is physisorption while that value is close to −20 kJ mol−1. Moreover, when the value is close to −40 kJ mol−1, it means that a coordinate covalent bond occurs between inhibitor substance and the surface, which known to be chemisorption. However, firstly, an electrostatic manner is necessary in all situations for the transportation of the inhibitor molecules to the surface of the metal. The value was computed as −35.47 kJ mol−1, demonstrating, inhibitor molecules adsorbed strongly on steel surface in such high corrosive test solution. Thus, both physical and chemical adsorptions take place between MS surface and PA compounds through electronegative N and O atoms and electron-rich –NH2 group. As a consequence, PA molecules and MS surface can be coordinated via N and O atoms, delocalized π electrons of PA and vacant d-orbitals of Fe, as a result of chemical adsorption.[44]