rJuorjns Oharnjsxry
rrorrj -ensDry "CD sippjjcsriijan
Lecturer: assist prof dr Matjaž KristI matiaz.kristl@uni-mb.si
University of Maribor, Slovenia
Faculty of Chemistry and Chemical Engineering
Department of Inorganic Chemistry
J Ik *^J J   ^>d -j ^>J J
>  R Lazarini, J. BrenSiS, Splošna in anorganska kemjja, DZS Ljubljana 1984 (pp, 280-301)
>   D, F, Shriver, P. W. Atkins, Inorganic Chemistry, Oxford university press 1999 (pp, 407 - 427)
>   Web sources
Inorganic LtierTvisUy

m n
"Perhaps one of you gentlemen would mind telling me jupt what it is outside the window that uo u find so attractive.
™
GönsraJ sJsiiJöniisiJ DroD^rtí^s
Atomic number: 9
Atomic weight: 18,998
Electron configuration: 1 s22s22px22py22pz1
Electronegativity (Allred - Rochow scale): 4,10
Ionic radius F~ : 1,36 Á
Covalent radius F; 0,71 Á Melting point:-219,6 °C Boiling point: -187,5 °C
i
3c-£ľDľJ3cjíi-£jyny
Dimensionless quantity!
Ability of an atom to attract electrons towards itself in a covalent bond
H			
2,20			
Li	Be	B	C
0,98	1,57	2,04	2,55
0,94	1,46	2,01	2,63
0,97	1,47	2,01	2,50
Na	Mg	Al	Si
0,93	1,31	1,61	1,90
0h93	1,32	1,31	2,44
1,01	1,23	1,42	1,74
K	Ca	Ga	Ge
0,82	1,00	1,81	2,09
0,80	-	1,95	-
0,91	1,04	1,82	2,02
Rb	Sr	(n	Sh
0,82	0,95	1,78	1,96
-	-	1,80	-
0,89	0,99	1,49	1,72
Cs	Ba	TI	Pb
0,79	G,B9	2,04	2,33
0,86	0,97	1,44	1,55
+ 1	+ 2	+ 3	+ 4
N 3,04 2,33 3,07
P 2,19
1,&1 2,06
As 2,18 1.75 2,20
Sb 2,05 1,65 1,82
Bi 2,02
1,67
O 3,44 3,17 3,50
S 2,58 2,41 2,44
Se 2.55 2,23 2,48
Te
2,10 2,01
F 3,98 3,31 4,10
Cl 3,16 3,00 2,83
3r
2,96 2.76 2,74
J 2,66 2,56 2,21
-3
-2
-1
Occurs/ICO and pr^ductJün
0,066 wt % in nature
Due to high reactivity, it can not be found in elementary state
Most common minerals:
>  fluorite, CaF2
>  apatite, Ca5F(P04)3 • cryolite, Na3AIF6
CrjüWiB, tti\j\\r
>  First described: 1799 from a deposit in Ivigtut, West Greenland.
>  Historically: ore of aluminium
> Today: electrolytic processing of bauxite, Al203 (lowers the
I melting point from > 2000 °C to < 1000 °C
j-J jsi o ry
♦  1530: 'fluorspar' (mainly CaF2) first described
♦  1670: glass is etched when exposed to fluorspar treated with acid
*  1700s: hydrofluoric acid is easily obtained by treating fluorite with concentrated sulfuric acid
*  1800s: many unsucessfull attempts to produce elemental fluorine from H, very dangerous - killing or blinding several scientists - "fluorine martyrs"
Moissan method (1886): isolation possible only by electrolysis, there is no stronger oxidizing agent:
CaF2 + H2S04 -» CaS04 + 2 HF
HF + KF -» KHF2
KHFo-»2KF + Ho + F
> High temperature electrolysis at 240°C (steel anode) or low temperature electrolysis at 90°C (Ni / C anode)
Ferdinand Frederic Henri Moissan, 1852 -1907 (Np 1906)
Low conductivity of HF! Melting temperatures: KFHF:217°C KP2HF: 72 °C KP3HF: 66 °C
in lei
|H2 outlet
F2 outlet
H2 outlet
HF/KF electrolyte
Steel cathode (—)
Carbon anode (+)
r2pruí\i\ďí}uíi p Jam (ErjcjJsjľjdJ:

U l»1!
i —.
Tr:   ÍJ
"      «'^:
>2
JsükriJrjcj f2by ďnsnnoc\\ íBiiďůon:
Karl O. Christe, University of South California (1986):
K2MnF6 + 2SbF5 -► 2KSbF6 + MnF4
2MnF4 -► 2MnF3 + F2
i i                   E	

i
r2 jjjüJscljJöj char/jJCsiJ pľupBľíJíS üffJuorjjjö
Bond length: 1,44 Á Short bond: strong repulsion ofnonbonding electron pairs —► weak bond —► highly reactive element! reacts with all elements other than He, Ne in Ar reactions are strongly exothermic
Atomorbital des       Molekül-        Atomorbital des einen F-Atoms           orbital           anderen F-Atomsl
|2p-0rbitale    fit  H
!$Orbitale
Some examples of reactions of elemental fluorine:
2H20 + 2F2 -► 02 + 4HF (explosive!)
>  Similar strongly exothermic reactions with all hydrogen containing compounds, e. g. H2S, NH3, H20
>  Reacts with H2 in dark at -200°C
>  By fluorinating, many elements form compounds with the highest possible oxidation state (e. g. PF5, SF6, IF7)
> With metals, the reactions are often moderate, at room T and normal pressure pasivisation of metals
>  Dry F at room T does not react with glass!
Muďí j/u p or hi mfJ u urin 3 coí/jpounds
HF: synthesis from elements theoretically possible, but inconvinient, expensive, dangerous!
Industrial methods:
CaFo + HoSO, -> CaSO. + 2HF
2Ca5F(P04)3 + 7H2S04 -+ 3Ca(H2P04) + 7CaS04 + 2HF
Anomalous high boiling point (HF +19°C; HCl -85°C HBr -67°C, HI -35°C) - try to explain why!
Most important properties of H F
>  High dipole moment, good solvent, many physical properties similar to water —► miscible in all proportions
>  Protolitic equilibrium:
HF + HF <+ H2F+ + P (K = 1-10"10)
>  HNO3 reacts as a base (!) in liquid HF:
HNO3 + HF -> H2N03+ + F-
> Very few compouds react as acids in HF:
SbF5 + 2HF -► H2F+ + SbF6-
> Aqueous solution (hydrofluoric acid) is a weak acid
HF + H20 -> H30+ + P (K = 7,2 • 10"4)
Reaction with glass:
Si02(s) + 4 HF(aq) Si02(s) + 6 HF(aq)
SiF4(g) + 2 H20(l) H2[SiF6](aq) + 2 H20(l)
Working with HF using glassware is impossible!
Use: etching of glass
ÜXüCüinpüiinÜB us sliioriľi 2F2 + 2NaOH -> 2NaF + 0F2 + H20
Colourless gas, very toxic, stable, does not react with water
02F2: prepared by subjecting a 1:1 mixture of gaseous fluorine and oxygen at low pressure to an electric discharge (Otto Ruff, 1933)
Unstable,     strong     oxidizing     and fluorinating agent
J/jdustrkiJ use vriluonne
l\) £íJ*JľJchnrj£ÍJ*jt UÍ LJľSJ/JJLJJ/J
Natural uranium: 99.2% U-238, 0.8% U-235
Problem: only 235U is fissionable by thermal neutrons
Low - enriched uranium (reactor grade): min. 3-4% U-235
Highly enriched uranium (weapons grade) min. 80 -90% U-235
Isotope separation: difficult, energy intensive (235U is on|y ! 26% lighter than 238U)
U308 + HNO3 -► U02(N03)2 U02(N03)2 + NH3 -► (NH4)2U20: (NH4)2U207 + H2 -► UO U02 + 4HF ->UF4 + 2H20 UF4 + F2 -► UF6 (g)
>  Separation by gasseous diffusion: forcing UF6 through semi-permeable membranes (obsolete, energy -consuming, separation factor per stage 1,005)
>  Separation by or gas centrifuges: centrifugal force presses U-238 toward the outside of the cylinder (less energy consuming, separation factor per stage 1,3)
560000 tonnes of depleted UF6 only in the USA!
industrií]J U23 os iliionn b) rJuuľoĽhJuľuhydľucnrb
Freones (CFCs): trade name for a group of chlorofluorocarbon and hydrochlorofluorocarbon compounds:
CCI3F (freon 11)
CCI2F2 (freon 12)
C2CI3F3 (freon 113)
2 isomeres: CCI3-CF3, CCI2F-CCIF2
Great properties: odorless, colorless, nonflammable, noncorrosive - ideal for use in air conditioning, refrigeration and fire-fighting systems.
Developed in 1930 {Migdley, Kettering) as an alternative to the toxic gases that were previously used as refrigerants: NH3, S02, CH3CI
WW2: use as automatic fire extinguishers in aircraft
1960s: CBrF3 (halon 1301)
CF2CIBr (halon 1211)
> among the most effective fire-fighting materials discovered!
>  By the late 1960s: standard in applications where
■ water and dry-powder extinguishers posed a threat of damage to the protected property, including computer rooms, telecommunications switches, laboratories, museums and art collections
1974: first warnings of damage to stratospheric ozone {Molina, Rowland)
Atmospheric time-series of CFC-11
Late 1980s, early 1990s: conventions for outphasing freones and (partially) halones from production (exception: Civilian and military aircraft!)
Northern hemisphere Southern hemisphere
1910    1920     1930     1940    1950     1960    1970     1980     1990    2000
Time [year]
Possible replacements: hydrofluorocarbons, HFCs
> 1,1,1,2-tetrafluoroethane, CF3-CH2F: refrigerant for domestic and car air conditioners, no ozone depleting properties (!), possible greenhoue effects
JrjdLJäíľhiJ IJ33 oTÍluoríno o) p o\y iBíľíjfl u or o s'thy \ on •
(C2F4)n:
•  Discovery: 1938, by accident when trying to synthesize C2F4
•  Use: cooking pans, textile fibers, chemical
industry (resistant to F2!) bearings, gaskets, medical implats, electronical devices
/ Guarantied
Td Kapp Yini Dry ">
GORE-TEX
rJ3<]JÍb JľJJpJjCSJ'£JOrj£í üVhllütifi
•  trace element (5g / 70 kg), in the form of F-
•  very nonuniform distribution throughout the body, most in bones and teeth
•  reduces tooth decay —► water fluoridation (0.5 -1 mg / L), controversial
Elemental F2 is highly toxic, LD50 =185 ppm (!!!)
•  Harmfull to lungs, skin and especially eyes - even 25 ppm cause strong eye irritarion.
Storing: iron, Ni - Cu alloy (monel), PTFE
PliionriB cjhöi/jjsnry research Jrj EjJovö/jjsj:
US Ljubljana, departement K1, prof. dr. Boris Žemva:
•  Synthesis and characterization of new coordination compounds with fluorine ligands, e. g.: XeF2, XeF4, KrF2) AsF3) HF etc.
•  Synthesis and characterization of ternary fluorides
•  Use of photochemical reactions and
1 elemental fluorine for the synthesis of new fluorine compounds of transition metals in high oxidation states
itaLft
JVkiľJbor
Syntheses and characterization of hydroxylammonium fluorometallates, (NH3OH)xMFy
• 1990 - 2009:12 scientific articles with JCR + 1 submitted (B. Volavšek, M. Drofenik, M. Kristl, I. Ban B. Dojer), 2 + 1 PhD theses, 3 MSc
«*.
•p».
W"
M = Ti, Zr, Hf, Al, Ga; In, Si, Ge, Cr, V, Co*, Cu*, Fe**
Structure of
P J LJ o r j r j b co/jj pounds uí nob\3 cjsiso
Bartlett, 1962: 'PtOF4' = 02+(PtF6)-
> first compound, in which oygen was oxidized!
>  Ej (O) = 1177 kJ/mol, Ej (Xe) = 1170 kJ/mol
Xe + PtF6 -+ Xe(PtF6)
Hoppe, 1962: Xe + F2 -► XeF2 (1 atm, 400°C)
>  strong oxidizing and fluorinating agent (XeF+ is formed)
>  reacts with water in alkaline solutions:
2XeF2 + 2H20 -► 2Xe + 4HF + 02
XeF4(1962):
Xe + 2F2-
XeF4 (6 atm, 400°C, Xe : F2 = 1 : 5)
solid compound, square planar geometry reacts with water:
3XeF„ + 6H20 -► Xe + 2 Xe03 + 12 HF
XeF6 (Slivnik et al., 1963):
Xe + 3F2 -► XeF6 (60 atm, 400°C, Xe : F2
•  solid compound, octahedral geometry
•  reacts with water:
XeF6 + H20 -► XeOF4 + 2HF XeFfi + 3H,0 -► Xe03 + 6HF
>  Recently also compounds with Xe -N and Xe - C bonds have been discovered, e. g. Xe(CF3)2 and XeFN(S02F)2
> Xe forms coordination compounds with unusually high coordination numbers:
XeF6 + CsF -► CsXeF7
2CsXeF7 -► XeF6 + Cs^eFg
>  Kr reacts with F in an electric field at -196°C:Kr+F2
(solid compound, stable only below -80°C,   extremely  strong   oxidizing
oriAnf An _v AnP  \