Transition metal + ligand + structures + isomerism

• What are transition metals defined as?

  Elements that form ion with an incomplete d-subshell
• How do transition metals differ from d-block elements?

  Scandium and zinc do not have incomplete d-subshells
• What ion does scandium form?

  Sc3+
• What is the electron configuration of Sc3+?

  [Ar] 3d0
• What ion does zinc form?

  Zn2+
• What is the electron configuration of Zn2+?

  [Ar] 3d10
• Which elements are in the first transition series?


  Titanium to copper
• What is the full electronic configuration of first d-series transition metals?

  • Follows the aufbau principle
  • Electrons occupy lowest energy sub-shells first
  • 4s fills before 3d
• What are the exceptions to the aufbau principle?


  Chromium and copper
• How does chromium's electron configuration differ from expected?

  Cr is [Ar] 3d5 4s1, not [Ar] 3d4 4s2
• How does copper's electron configuration differ from expected?

  Cu is [Ar] 3d10 4s1, not [Ar] 3d9 4s2
• What is the electron configuration of an iron atom?

  1s22s22p63s23p63d64s2
• What is the electron configuration of Fe2+ ion?

  1s22s22p63s23p63d6
• What is the electron configuration of Fe3+ ion?

  1s22s22p63s23p63d5
• What are the general properties of transition metals?

  • Variable oxidation states
  • Form complex ions
  • Form coloured compounds
  • Behave as catalysts

  
• Why do transition metals have variable oxidation states?


  They can lose different numbers of electrons
• How are oxidation states indicated for transition metals?

  Using Roman numerals

  
• What is a complex ion?

  A central metal atom/ion with surrounding ligands
• What is a ligand?

  A molecule or ion surrounding a central atom
• How do ligands interact with transition metals?

  They donate lone pairs of electrons
• What is the coordination number?

  Number of co-ordinated bonds to the central atom
• What are mono-dentate ligands?

  Ligands that form one dative bond
• What are bidentate ligands?

  Ligands that form two dative bonds
• What geometries can transition element complexes have?

  • Six-coordinate complexes: octahedral
  • Four-coordinate complexes: tetrahedral or square planar

  
• What is the bond angle in octahedral complexes?

  90 degrees
• What is the bond angle in tetrahedral complexes?

  109.5 degrees

  
• What is the bond angle in square planar complexes?

  90 degrees

  
• What types of isomerism can transition element complexes exhibit?

  • Geometrical (cis-trans) isomerism
  • Optical isomerism
• What is geometrical isomerism in transition metal complexes?

  Different arrangements of ligands around the metal
• Why is cis-platin effective in cancer treatment?

  It binds to DNA in cancer cells

  
• How does cis-platin enter cells?

  Through ligand exchange with water molecules

  
• What is the adverse effect of cis-platin treatment?

  Hair loss due to healthy cell damage
• What is the balance needed in cancer treatment with cis-platin?

  • Effectiveness against cancer cells
  • Minimizing damage to healthy cells
• What is a new therapeutic pathway in cancer treatment?

  Targeting cancer cells while sparing healthy cells