• Paramagnetic compounds have unpaired electrons and are Paramagnetic compounds have unpaired electrons and are attracted to an external magnetic field.attracted to an external magnetic field.

• Liquid oxygen is paramagnetic. It is attracted to an external Liquid oxygen is paramagnetic. It is attracted to an external magnetic field.magnetic field.

CH 103: THE MAGNETIC SUSCEPTIBILITY OF TRIS-CH 103: THE MAGNETIC SUSCEPTIBILITY OF TRIS-ETHYLENEDIAMINE NICKEL (II) CHLORIDE, [Ni(en)ETHYLENEDIAMINE NICKEL (II) CHLORIDE, [Ni(en)33]Cl]Cl22

PARAMAGNETIC COMPOUNDSPARAMAGNETIC COMPOUNDS

• In contrast, diamagnetic In contrast, diamagnetic compounds have no compounds have no unpaired electrons and are unpaired electrons and are repelled by both poles of an repelled by both poles of an external magnetic field. external magnetic field. That is, diamagnetic That is, diamagnetic compounds form an compounds form an induced magnet field in the induced magnet field in the opposite direction of an opposite direction of an external magnetic field.external magnetic field.

• Graphite is diamagnetic. It Graphite is diamagnetic. It is repelled by an external is repelled by an external magnetic field.magnetic field.

• The first objective of today’s The first objective of today’s experiment is to determine experiment is to determine if [Ni(en)if [Ni(en)33]Cl]Cl22 is is

paramagnetic or paramagnetic or diamagnetic.diamagnetic.

DIAMAGNETIC COMPOUNDSDIAMAGNETIC COMPOUNDS

• What is the electron configuration of scandium metal, Sc?What is the electron configuration of scandium metal, Sc?• Sc(Z=21): 1sSc(Z=21): 1s22 2s 2s22 2p 2p66 3s 3s22 3p 3p66 4s 4s22 3d 3d11

• What is the electron configuration of scandium ion, ScWhat is the electron configuration of scandium ion, Sc2+2+??• Hint: The outmost s electrons of a transition metal are Hint: The outmost s electrons of a transition metal are

generally removed before the outmost d electrons.generally removed before the outmost d electrons.• ScSc2+2+(Z=21): 1s(Z=21): 1s22 2s 2s22 2p 2p66 3s 3s22 3p 3p66 3d 3d11

• The d orbital energy level diagram for ScThe d orbital energy level diagram for Sc2+2+ follows. Is Sc follows. Is Sc2+2+ paramagnetic or diamagnetic?paramagnetic or diamagnetic?

or more accuratelyor more accurately

• Paramagnetic, ScParamagnetic, Sc2+2+ has 1 unpaired electron. has 1 unpaired electron.

d ORBITAL ENERGY LEVEL DIAGRAMSd ORBITAL ENERGY LEVEL DIAGRAMS

THE GRAM MAGNETIC SUSCEPTIBILITY, χTHE GRAM MAGNETIC SUSCEPTIBILITY, χgg

• Use the periodic table in the front of your laboratory manual Use the periodic table in the front of your laboratory manual to calculate the molecular weight o of the sample, to calculate the molecular weight o of the sample, [Ni(en)[Ni(en)33]Cl]Cl22 or [Ni(NH or [Ni(NH22CHCH22CHCH22NHNH22))33]Cl]Cl22..

THE MOLAR MAGNETIC SUSCEPTIBILITY, χTHE MOLAR MAGNETIC SUSCEPTIBILITY, χMM

• The ethylenediamine ligands (NHThe ethylenediamine ligands (NH22CHCH22CHCH22NHNH22) and the ) and the

chloride ions (Clchloride ions (Cl--) are diamagnetic and are repelled by the ) are diamagnetic and are repelled by the external magnetic field.external magnetic field.

• Therefore, the deflection (D) is artificially small, and the Therefore, the deflection (D) is artificially small, and the Molar Magnetic Susceptibility (χMolar Magnetic Susceptibility (χMM) is artificially small.) is artificially small.

• This is corrected by the following equation.This is corrected by the following equation.

THE CORRECTED MOLAR MAGNETIC SUSCEPTIBILITY, χTHE CORRECTED MOLAR MAGNETIC SUSCEPTIBILITY, χAA

THE CORRECTED MOLAR MAGNETIC SUSCEPTIBILITY, χTHE CORRECTED MOLAR MAGNETIC SUSCEPTIBILITY, χAA

THE MAGNETIC MOMENT AND THE MAGNETIC MOMENT AND

THE NUMBER OF UNPAIRED ELECTRONSTHE NUMBER OF UNPAIRED ELECTRONS

• Calculate the magnetic moment from the following Calculate the magnetic moment from the following equation.equation.

• Calculate the number of unpaired electrons (n) from the Calculate the number of unpaired electrons (n) from the following equation.following equation.

SAFETYSAFETY

• Give at least 1 safety concern about using Give at least 1 safety concern about using [Ni(NH[Ni(NH22CHCH22CHCH22NHNH22))33]Cl]Cl22 in today’s experiment. in today’s experiment.

• This is an irritant. Wear your goggles at all times. This is an irritant. Wear your goggles at all times. Immediately clean all spills. If you do get either of these in Immediately clean all spills. If you do get either of these in your eye, immediately flush with water.your eye, immediately flush with water.

• Your laboratory manual has an extensive list of safety Your laboratory manual has an extensive list of safety procedures. Read and understand this section.procedures. Read and understand this section.

• Ask your instructor if you ever have any questions about Ask your instructor if you ever have any questions about safety.safety.

SOURCESSOURCES

• ““Diamagnetic graphite levitation” by en:User:Splarka - Diamagnetic graphite levitation” by en:User:Splarka - English Wikipedia. Licensed under Public domain via English Wikipedia. Licensed under Public domain via Wikimedia Commons - Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Diamagnetic_graphite_levcommons.wikimedia.org/wiki/File:Diamagnetic_graphite_levitation.jpg#mediaviewer/itation.jpg#mediaviewer/File:Diamagnetic_graphite_levitation.jpg [accessed 28 File:Diamagnetic_graphite_levitation.jpg [accessed 28 August 2014].August 2014].

• McMurry, J., R.C. Fay. 2004. Chemistry, 4th ed. Upper McMurry, J., R.C. Fay. 2004. Chemistry, 4th ed. Upper Saddle River, NJ: Prentice Hall.Saddle River, NJ: Prentice Hall.

• ““Paramagnetism of liquid oxygen” by Pieter Kuiper - Own Paramagnetism of liquid oxygen” by Pieter Kuiper - Own work. Licensed under Public domain via Wikimedia work. Licensed under Public domain via Wikimedia Commons - Commons - http://commons.wikimedia.org/wiki/File:Paramagnetism_of_http://commons.wikimedia.org/wiki/File:Paramagnetism_of_liquid_oxygen.jpeg#mediaviewer/liquid_oxygen.jpeg#mediaviewer/File:Paramagnetism_of_liquid_oxygen.jpeg [accessed 28 File:Paramagnetism_of_liquid_oxygen.jpeg [accessed 28 August 2014].August 2014].

• Petrucci, R.H. 1985. General Chemistry Principles and Petrucci, R.H. 1985. General Chemistry Principles and Modern Applications, 4th ed. New York, NY: Macmillan Modern Applications, 4th ed. New York, NY: Macmillan Publishing Company.Publishing Company.