28.2.5—Shapes of transition metal complexes

Common complex geometries are linear (2 sites, 180°), square planar (4, 90°), tetrahedral (4, about 109.5°) and octahedral (6, 90° between adjacent sites).

Geometry depends on coordination number, ligand size, metal and electronic configuration. Use the stated complex rather than assigning a shape from charge alone.

[Ag(NH₃)₂]⁺ is linear; [PtCl₄]²⁻ square planar; [CoCl₄]²⁻ tetrahedral; [Cu(H₂O)₆]²⁺ octahedral (often distorted).

Four-coordinate does not uniquely mean tetrahedral—square-planar complexes are also possible.