Pentatomic (true halogens)

• 
  Methane (methyl hydride)
• 
  Fluoromethane (methyl fluoride)
• 
  Chloromethane (methyl chloride)
• 
  Bromomethane (methyl bromide)
• 
  Iodomethane ( methyl iodide)

Hexatomic

• 
  Acetonitrile (methyl cyanide)
• 
  Isocyanomethane ( methyl isocyanide)
• 
  Methanol (methyl hydroxide)
• 
  Methanethiol (methyl hydrosulfide)
• 
  Methaneselenol (methyl hydroselenide)
• 
  Methanetellurol (methyl hydrotelluride)