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The reason for the hydrolysis is the high electrical charge density on the zinc ion, which pulls electrons away from an OH bond of a coordinated water molecule and releases a hydrogen ion. The polarizing effect of Zn 2+ is part of the reason why zinc is found in enzymes such as carbonic anhydrase. Structure of a monomeric zinc ...
A water molecule in the first solvation shell of an aqua ion may exchange places with a water molecule in the bulk solvent. It is usually assumed that the rate-determining step is a dissociation reaction. [M(H 2 O) n] z+ → [M(H 2 O) n-1] z+ * + H 2 O. The * symbol signifies that this is the transition state in a chemical reaction. The rate of ...
Simultaneously, the water molecule coordinated to zinc is deprotonated by Glu-270 and interacts with the carbonyl stabilized by Arg-127. This creates an intermediate, shown in Figure 2, where the negatively charged oxygen is coordinated to zinc, and through unfavorable electrostatic interactions between Glu-270 and the ionized product ...
The structure of the active site in carbonic anhydrases is well known from a number of crystal structures. It consists of a zinc ion coordinated by three imidazole nitrogen atoms from three histidine units. The fourth coordination site is occupied by a water molecule. The coordination sphere of the zinc ion is approximately tetrahedral.
The pyrithione ligands, which are formally monoanions, are chelated to Zn 2+ via oxygen and sulfur centers. In the crystalline state, zinc pyrithione exists as a centrosymmetric dimer (see figure), where each zinc is bonded to two sulfur and three oxygen centers. [3] In solution, however, the dimers dissociate via scission of one Zn-O bond ...
A dramatic example is the conversion of methanol into hexamethylbenzene using zinc chloride as the solvent and catalyst: [48] 15 CH 3 OH → C 6 (CH 3) 6 + 3 CH 4 + 15 H 2 O. This kind of reactivity has been investigated for the valorization of C1 precursors. [49] Examples of zinc chloride as a Lewis acid include the Fischer indole synthesis: [50]
Zinc nitrate is an inorganic chemical compound with the formula Zn(NO 3) 2. This colorless, crystalline salt is highly deliquescent. It is typically encountered as a hexahydrate Zn(NO 3) 2 ·6H 2 O. It is soluble in both water and alcohol.
Zn, the most abundant isotope of zinc, is very susceptible to neutron activation, being transmuted into the highly radioactive 65 Zn, which has a half-life of 244 days and produces intense gamma radiation. Because of this, zinc oxide used in nuclear reactors as an anti-corrosion agent is depleted of 64 Zn before use, this is called depleted ...