Putting All Minerals in Perspective Chemical Properties of Minerals I

P C N H O S Carbohydrates and Fats Proteins Nucleic Acids Creating the molecules of life So, why do we need more?

But…will these six elements give us life? give us movement? allow us to grow and develop? generate energy? maintain internal homeostasis? build bones and teeth? maintain fluid balance? Will they…. stimulate muscles to contract? propagate nerve impulses? determine the color of fur and skin? optimize our immune system?

What chemical elements do we associate with life? NaKCaMgCl PCNHOS FeZnCuMnSe VSiAsMoI Co NiCr BrF SnB ? 28?

Chemical Principles Underlying the Properties of Minerals

First transition series Macrominerals Microminerals 3d3d 4d4d 5d5d Noble Gases Iodine ( heaviest ) Non-metals

Properties of Minerals Relevant to Function and Selection

5 major properties related to a particular mineral’s function and selection 1. Charge or valance state of the ion 2. Solubility in water 3. Redox property 4. Coordination geometry 5. Choice of ligand

Valance State of Macro- and Microminerals MacroMicro SodiumNa + IronFe 2+, Fe 3+,Fe 4+ PotassiumK + ZincZn 2+ MagnesiumMg 2+ CopperCu +, Cu 2+,Cu 3+ CalciumCa 2+ ManganeseMn 2+,Mn 4+,Mn 5+ ChlorineCl - CobaltCo +, Co 2+, Co 3+ NickelNi +, Ni 2+ MolybdenumMo 4+, Mo 5+,Mo 6+ IodineI - Denotes most common oxidation states in solution at neutral pH

Solubility in Water Rule: A mineral that is freely soluble in water can easily move through extracellular and intracellular fluids. Rule: Paradoxically, charge on the molecule is not the only determinant of water solubility, atomic number must also be considered Rule: Minerals capable of “hydrolyzing” water work against solubility

Solubility varies with charge and atomic number Na +, K M Ion/complex Mg 2+, Ca M Zn M Cu 2+ Fe M M Macrominerals Microminerals pH 7.0 with chloride as counter ion

Metals as hydrolytic agents Fe H 2 O Fe(OH) 3 + 3H + Insoluble hydroxide Cu H 2 O Cu(OH) 2 + 2H + H+H+ Acid (low pH) favors solubility

Oxidation-Reduction (redox metals) Rule: Metals with multiple valance states have the capacity to take and give electrons, thereby acting as oxidizing and reducing agents, respectively. Corollary: Fixed valence metals cannot behave as redox agents Cu 2+ + Fe 2+ Cu + + Fe 3+ Copper is reduced, iron is oxidized Copper is oxidized, iron is reduced Zn 2+ + Fe 2+ No reaction

Coordination Complexes Rule: Metal ions, especially micro- adhere to a strict configuration in number of ligands and spatial orientation when forming complexes Rule: Adherence to coordination requirements has a major impact on selection of a particular metal ion for a function and rejection of others to replace the selected one. Rule: Metal ion antagonism and synergism is strongest when two metals have the same coordination properties

3d 10 3d 9

Cu + (tetrahedral)d 10 dsp 3 4 Zn 2+ (tetrahedral)d 10 dsp 3 4 Cd 2+ (tetrahedral)d 10 dsp 3 4 Hg 2+ (linear)d 10 dsp2 Cu 2+ (sq. plan)d 9 dsp 2 4 Ag 2+ (sq. plan)d 9 dsp 2 4 Fe 2+ (octahedral)d 5 d 2 sp 2 6 Ion Orbital ConfigCoordination No.