1. Lecture 20. The d-Block Elements. VII-VIII B groups
PhD. Halina Falfushynska

2. Manganese
Manganese is obtained mainly from the mineral pyrolusite, MnO2.
Ferromanganese alloys are wear resistant and shock resistant and are used for railroad tracks, bulldozers, and road scrapers.
Manganese(IV) oxide is the starting point for making most other manganese compounds.
Potassium permanganate, KMnO4, is an important oxidizing agent that is used in both analytical and organic chemistry laboratories, and in water treatment.

3. The Iron Triad: Fe, Co, and Ni
Iron is the fourth most abundant element in Earth’s crust. Cobalt and nickel are not nearly as common.
All three elements form 2+ and 3+ ions.
The most common ions of Co and of Ni are the 2+. The most common ion of Fe is the 3+ due to the half-filled d-subshell:

4. Ferromagnetism
The iron triad exhibits ferromagnetism which is a much stronger magnetic effect than paramagnetism.
A ferromagnetic solid consists of regions called domains in which atoms have their magnetic moments aligned.
When placed in a magnetic field, all the domains are aligned and the solid becomes magnetized.

7. Manganese Mn (Manganum)
Manganese Mn (Manganum)
trace element
cofactor of enzymes: superoxide dismutase
pyruvate carboxylase
KMnO Potassium permanganate (INN: Kalii permanganas)
- in water dissolves to give deep purple solutions
- strong oxidizing agent
- dilute solutions can act as desinfectant

8. Fe in food 10-30 mg/day absorption: only 7-10%  ~ 1 mg/day
Iron Fe (Ferrum)
important microelement
human body: 4–5 g Fe
a) functional form - heme iron proteins hemoglobin 70 % myoglobin %
some enzymes
- non-heme iron proteins
b) tranport form (transferrin)
c) storage of iron (ferritin, hemosiderin)-20 %
Fe in food mg/day absorption: only 7-10%  ~ 1 mg/day

9. HEME iron proteins Hemoglobin - O2 transport in blood
HEME iron proteins
Hemoglobin - O2 transport in blood
- in red blood cells
- tetramer = 4 subunits
(each subunit: one heme + one globin)
HbA ("adult") a2b2
HbF ("fetal") a2g2
Myoglobin - "O2 storage" in muscle cell
Cytochromes - electron transport
- their function is based on: Fe2+ (reduced) Fe3+ (oxidized)
heme

10. iron–sulphur proteins (FeS proteins)
Non-heme iron proteins FeII or FeIII bound to protein SH
iron–sulphur proteins (FeS proteins)
Transferrin - blood plasma protein ( b1 globulin )
- transport of Fe
- 1 molecule of transferrin can carry 2 iron ions in form of Fe3+
Ferritin - intracellular iron storage protein (liver, bone marrow)
- 1 ferritin complex can store about 4500 Fe3+
- ferritin without iron = apoferritin
Hemosiderin - "damaged (Fe-overloaded) ferritin" - Fe from it is less available

11. OVERVIEW OF IRON METABOLISM
OVERVIEW OF IRON METABOLISM
liver
FERRITIN
HEMOSIDERIN
blood plasma
TRANSFERRIN
bone marrow
red blood cells
HEMOGLOBIN
spleen
tissues
CYTOCHROMES
Fe-S proteins
muscles
MYOGLOBIN
BLEEDING (Fe losses)
FOOD

12. Iron metabolism = unique - reutilization ! (closed system)
Iron metabolism = unique
- reutilization ! (closed system)
NO regulated excretion system for Fe !
Fe absorption must be "regulated"
Loss of Fe  through loss of blood (females mestrual bleeding)
Iron deficiency - microcytic anemia "iron deficiency anemia"
Iron overload - hemochromatosis = accumulation of iron in the body
(depositions as hemosiderin)
organ dysfunction (liver, heart, ...)

13. IRON ABSORPTION FOOD Fe3+ STOMACH Fe2+ Fe3+ BLOOD transferrin (Fe3+)
IRON ABSORPTION
FOOD Fe3+
STOMACH
HCl pH 1-2
ascorbic acid
gastroferrin - iron binding protein
reduction
Fe2+
Fe3+
BLOOD
transferrin (Fe3+)
ferritin (Fe3+)
apoferritin
Fe2+
INTESTINAL MUCOSA CELL