Coordination Compounds

They donate electron pairs to the central metal, They can be ions or neutral molecules, They form coordinate bonds with metals

Ligands are species that donate electron pairs to form coordinate bonds with central metal atoms/ions. They can be anions (like Cl-), neutral molecules (like NH3, H2O), or even cations in rare cases. They are not always negatively charged - NH3 and H2O are neutral ligands.

Ligands are named before the metal, Anionic ligands end in -o, The metal in an anionic complex ends in -ate, Oxidation state is shown in Roman numerals, Cation is always named first

All these are correct IUPAC naming rules: ligands come before metal in naming, anionic ligands end in -o (chloro, cyano), metals in anionic complexes end in -ate (ferrate, chromate), oxidation states use Roman numerals in parentheses, and cations are named first regardless of charge.

Crystal Field theory

Crystal Field Theory explains the color of coordination compounds through d-d electronic transitions. When ligands approach the metal ion, d orbitals split into different energy levels. Light absorption occurs when electrons transition between these split d orbitals, giving rise to color.

t2g and eg

In octahedral crystal field, the five d orbitals split into two sets: t2g (lower energy, containing dxy, dxz, dyz) and eg (higher energy, containing dx2-y2, dz2). The t2g orbitals are directed between the ligands while eg orbitals point directly toward the ligands.