Chapter 20: Transition Metals

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Chapter 20 Transition Metals Coordination
Chemistry

• Figure 20.1 The Position of the Transition
  Elements on the Periodic Table

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• Transition Metal has partially filled
  d-orbitals in metal or common oxidation states
  (d1 d9)
• Inner Transition Metal has partially filled
  f-orbitals
• Exhibit similarities within a period as well as a
  group, whereas representative metals exhibit
  similarities only within a group.
• Properties most hard strong, good electrical
  thermal conductivity, metallic luster, variable
  oxidation state, many paramagnetic ions, many
  colored ions

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• Complex Ions transition-metal ion covalently
  bonded to a number of Lewis bases (ligands)
• Ni2 6 NH3 ? Ni(NH3)62
• Co2 4 Cl ? CoCl42
• Recall from lab FeSCN2, Co(H2O)62
• Electron Configurations recall Aufbau principle
  (section 7.11)
• Sc Ar4s23d1
• Cr Ar4s13d5
• Cu Ar4s13d10

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• Electron Configurations of Ions
• Lose es of highest n-value first.
• Sc2 Ar3d1
• Cr2 Ar3d4
• Oxidation States see Table 20.2
• Exs V 2, 3, 4, 5
• Mn 2, 3, 4, 7
• Co 2, 3
• Ionization Energies see Figure 20.2

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Figure 20.2Plots of the First (Red Dots) and
Third (Blue Dots) Ionization Energies for the
First-Row Transition Metals
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• Reducing Strength Table 20.3
• M(s) ? Mn(aq) n e
• Lower E indicates stronger reducing agent
• Sc3 3 e ? Sc E 2.08 V
• Cu2 2 e ? Cu E 0.34 V
• All metals with negative E will dissolve in acid
  to release H2
• Fe(s) 2 H(aq) ? Fe2(aq) H2(g)
• ?E 0.00 (0.44) 0.44 V

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• Atomic Radii
• Main groups increase down a group, decrease
  across a period as Z increases
• Transition metals decrease across a period,
  increase from 3d to 4d, but 4d 5d metals
• Lanthanide contraction 5d metals smaller than
  expected due to the presence of the lanthanides
  and addition of 14 protons immediately before
  starting 5d series
• 4d 5d metals very similar in behavior

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Figure 20.3Atomic Radii of the 3d, 4d , and 5d
Transition Series