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The nitrogen atom has only 6 electrons assigned to it. One of the lone pairs on an oxygen atom must form a double bond, but either atom will work equally well. Therefore, there is a resonance structure. Tie up loose ends. Two Lewis structures must be drawn: Each structure has one of the two oxygen atoms double-bonded to the nitrogen atom.
Thiocyanate [6] is known to be an important part in the biosynthesis of hypothiocyanite by a lactoperoxidase. [7] [8] [9] Thus the complete absence of thiocyanate or reduced thiocyanate [10] in the human body, (e.g., cystic fibrosis) is damaging to the human host defense system.
Structure of Co(SCN) 2 (H 2 O) 3. The structures of Co(SCN) 2 and its hydrate Co(SCN) 2 (H 2 O) 3 have been determined using X-ray crystallography. [1] Co(SCN) 2 forms infinite 2D sheets in the mercury(II) thiocyanate structure type, where as Co(SCN) 2 (H 2 O) 3 consists of isolated tetrahedral Co(SCN) 2 (H 2 O) 2 centers and one equivalent of water of crystallization.
HSAB is an acronym for "hard and soft (Lewis) acids and bases".HSAB is widely used in chemistry for explaining the stability of compounds, reaction mechanisms and pathways. It assigns the terms 'hard' or 'soft', and 'acid' or 'base' to chemical species.
The esters of thiocyanic acid have the general structure R−S−C≡N, where R stands for an organyl group. Isothiocyanic acid, HNCS, is a Lewis acid whose free energy, enthalpy and entropy changes for its 1:1 association with a variety of Lewis bases in carbon tetrachloride solution at 25 °C have been reported.
A Lewis base, then, is any species that has a filled orbital containing an electron pair which is not involved in bonding but may form a dative bond with a Lewis acid to form a Lewis adduct. For example, NH 3 is a Lewis base, because it can donate its lone pair of electrons.
In chemistry, an electron pair or Lewis pair consists of two electrons that occupy the same molecular orbital but have opposite spins. Gilbert N. Lewis introduced the concepts of both the electron pair and the covalent bond in a landmark paper he published in 1916. [1] [2]
The structure of Cu(SCN) 2 was determined via powder X-ray diffraction and consists of chains of Cu(NCS) 2 linked together by weak Cu–S–Cu bonds into two-dimensional layers. It can be considered a Jahn–Teller distorted analogue of the mercury thiocyanate structure-type. Each copper is octahedrally coordinated by four sulfurs and two ...