COMPLEXES and CHELATING AGENTS

2nd ppt

Coordination Compounds

Specialized compounds involving metal atoms that bond with additional anions or molecules called ligands after satisfying normal valence requirements.

Ligands

Molecules or ions that surround and bind directly to the central metal atom in a complex through their donor atoms or positions.

Werner's Theory

The widely accepted theory of complex ion formation, proposing the existence of a secondary valence and characteristic geometries for ligands.

Coordination Number

The maximum number of donor atoms that can surround the central metal atom in a complex, determining the geometry of the compound.

Naming Coordination Compounds

The cation is named before the anion, ligands are named first in alphabetical order, and the metal ion is named last. Greek prefixes are used to indicate the number of ligands present.

Geometric Isomers

Isomers that have the same molecular formula but differ in the spatial arrangement of their atoms. They are distinguished as "cis" or "trans."

Sodium Nitroprusside

A compound used in acute hypertensive crises that releases nitric oxide in the systemic circulation but can cause cyanide toxicity.

Cisplatin

A platinum compound used as an anti-cancer agent that forms cross-links with DNA, potentially causing severe side effects.

Carboplatin

A platinum compound similar to cisplatin but with a bidentate dicarboxylate ligand, reducing nephrotoxic effects.

Chelate

A cyclic or ring structure consisting of a central metal atom attached to a ligand, known for its stability when the total number of atoms in the ring is five, six, or seven.

Calcium Disodium Edetate

The calcium complex of the disodium salt of ethylenediaminetetraacetic acid, used in the treatment of lead poisoning.

Dimercaprol

A neutralizing agent for arsenical war gases that forms stable mercaptides of metals, excreted in the urine.

Penicillamine

Used to improve copper excretion in Wilson's disease, reducing copper (II) to copper (I) in the tissues.

Deferoxamine

A chelating agent used in the treatment of acute iron toxicity.

Cyanocobalamin

A form of vitamin B12 used to treat pernicious anemia.

Sequestering Agents

Polydentate ligands used to improve solubility and stabilize metal atoms by chelation. Examples include Benedict's reagent and Fehling's reagent.