1 / 12

Transition Metals & Complex ions

Transition Metals & Complex ions. State and give examples of complexes with six-fold coordination with an octahedral shape Describe and use the terms: complex ion and coordination number . Explain the term ligand in terms of coordinate bonding.

gabi
Download Presentation

Transition Metals & Complex ions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Transition Metals & Complex ions • State and give examples of complexes with six-fold coordination with an octahedral shape • Describe and use the terms: complex ion and coordination number. • Explain the term ligand in terms of coordinate bonding.

  2. Definition Hangman – Coordinate bond (aka – dative covalent bond) A shared pair of electrons in which thebonded pair has been provided by one ofthebonding atoms only. _ / _ _ _ _ _ _ / _ _ _ _ / _ _ / _ _ _ _ _ _ _ _ _ / _ _ / _ _ _ _ _ / _ _ _ / _ _ _ _ _ _ / _ _ _ _ / _ _ _ / _ _ _ _ / _ _ _ _ _ _ _ _ / _ _ / _ _ _ / _ _ / _ _ _ / _ _ _ _ _ _ _ / _ _ _ _ _ / _ _ _ _.

  3. Complex ion [Fe(H2O)6]2+ Each of the six H2O ligands forms one coordinate (dative covalent) bond to the central metal ion using a lone pair of electrons from its oxygen atom. This complex ion has a coordination number of six (the number of coordinate bonds to the central metal ion)

  4. Charges on complex ions The overall charge of a complex ion is the sum of the individual charges of the transition metal ion and those of the ligands. Example State the formula and charge of the complex ion made from one Iron (II) ion and 6 cyanide molecules. [Fe(CN)6]4- All of these ligands are classed as monodentate ligands (i.e. They only donate one pairof electrons to the central metal ion)

  5. Formulae Questions • State the formula & charge of each of these complex ions: • One copper (II) ion & four chloride ions • One iron (III) ion & five water molecules & a chloride ion. • One copper (II) ion & four ammonia molecules & two hydroxide ions • One cobalt (III) ion & four hydroxide ions • What is the oxidation number of the transition metal in each of these complex ions. • [Fe(CN)6]3- • [Co(SCN)4]2- • [Cu(CN)4(Cl)2]4- • [Ti(H2O)3OH]2+

  6. 3D shapes of complex ions Most common shape = octahedral( 6 coordinate bonds) BOND ANGLE = all 90o

  7. 3D shapes of complex ions The copper(II) and cobalt(II) ions have four chloride ions bonded to them rather than six, because the chloride ions are too big to fit any more around the central metal ion. Less common shape = tetrahedral( 4 coordinate bonds) BOND ANGLE = all 109.5o

  8. Shapes of complex ions Questions For each of the 8 complex ions you worked with during “formulae questions” draw the 3D shape using the wedge shaped bonds, show the bond angles and name the shape.

  9. Reminder – what is a stereoisomer? • Molecules or complexes with the same structural formula but with a different arrangement of the atoms in space.

  10. Stereoisomerism in complex ions Cis–trans isomerism in [Co(NH3)4Cl2]+ Chloride ligands at 90o to each other Chloride ligands at 180o to each other

  11. Stereoisomerism in complex ions Cis–trans isomerism in [NiCl2(NH3)2] 4 coordinate bonds – alternative to tetrahedral = Square Planar BOND ANGLE = all 90o

  12. Structure of cis-platin Effective cancer treatment – Thought to bind to and alter cancer cell DNA and therefore prevent their growth and reproduction • What is the formula for cis-platin? • Explain why this molecule uses the prefix “cis” in its name.

More Related