Inorganic Chemistry- Special Topics Flashcards
Transmetallation
M + M’R -> MR + M’, where M is a metal that is more electropositive than M’
Double displacement
MR + EX -> MX + ER, where E is a p-block element metalloid and M is more electropositive than E
Hydrometallation
MH + H2C=CH2 -> MH2C-CH3, in the case of unsymmetrical Allene’s, the M group attaches to the less hindered carbon atom, and the smaller H attaches to the most hindered C
S block elements form organometallic compounds that have what type of bonds?
Highly polar M+-C- bonds; the ionic character of these bonds increases for the heavier elements
Polarity of s-block organometallics vs group 3 organometallics
Group 3 organometallic compounds are more polar in nature
Group 3 nucleophilic character trend:
AlR3>GaR3>BR3; BR3 & GaR3 compounds are unassociated planar trigonal molecules
Group 4 organometallic polarity
Not very polar and organometallic compounds are electron-poor
Group 4 organometallic geometry
Tetrahedral
Group 4 organometallic resistance to hydrolysis
Resistance is due to low polarity of their bonds and the steric hinderance around the center atom
Group 5 organometallic geometry
Trigonal pyramidal
Group 5 organometallic compounds electron density
Electron rich; Lewis basicity arises due to the presence of a lone pair of e- on the center atom
Hapticity
The # of atoms of a ligand that are attached to a metal atom; ranges from 1-8
Group 6, 7, & 8 organometallic compounds generally have
18 valence electrons around their central metal atom
Toxic organometallic compounds
Organomercury, organoptin, organolead, organoarsenic, organosilicon
Biomethylation
Creation of organometallic compounds created in the environment starting from inorganic precursors
Catalyst
A substance that increases the rate of a chemical reaction without being consumed; they act by lowering the activation energy of rxns
Homogenous catalysis
The catalyst and reagents are present in the same phase
Heterogeneous catalysis
The catalyst is present in a phase different from that of the reactants; solids and are usually easily separated from the products of the rxns
Turnover frequency
N, the ratio of he rate of rxn (v) over the concentration of the catalyst [C] in a homogenous catalyst or the amount of catalyst in a heterogeneous catalyst
Four distinct characteristics of catalytic process
- ) must be thermodynamically favorable
- ) fast enough to be useful
- ) catalyst = selective and yield high proportion of desired product
- ) have a long lifetime and not be altered over many rxns
Homogenous Catalytic process of hydrocarbon formation
- ) coordination and issociation of reactants and catalyst
- ) migration
- ) nuchleophilic attack
- ) oxidation and reduction
- ) oxidative addition
Materials chemistry
Solid state chemistry; the synthesis, structure, properties, and applications of solid materials
Defect structure
Aspect of solids that affect properties such as electrical conductivity, mechanical strength, corrosion, and chemical reactivity
Point defects
Occur at single sites; can be intrinsic or extrinsic
Extended defects
occur in 1, 2, or 3 dimensions; can be intrinsic or extrinsic
Intrinsic defects
Present for strictly thermodynamic reasons: the presence of defects I. Solids introduces disorder increasing entropy of the system
Two types of intrinsic defects
Schottky defect
Frenkel defect
Schottky defect
Corresponds to a. Vacancy; a point defect in which an atom or ion is missing from the usual site
Frenkel defect
A point defect in which an atom or ion has been displaced from to an interstitial site in the lattice
Extrinsic defects
Can be controlled by synthetic conditions and purification of the solid
Optical properties
Introduced via extrinsic defects; they change the way light passes through a solid
Superconductors
Possess the ability to conduct electricity without resistance; have structures related to that of perovskites
