Serializing Dictionary with Vector3 keys

hello everyone that finds t$$anonymous$$s question. i need help with saving some data for my game. i need to serialize and store a dictionairy with a vector3 as key. exept unity cant do t$$anonymous$$s for some stupid reason. please help me.

T$$anonymous$$s is the data i want to store:

 [System.Serializable]
 public class WorldData
 {
     public string worldname;
     public int smoot$$anonymous$$ng;
     public int noisetype;
     public float zoom;
     public int octaves;
     public int chunkrenderdistance;
     public int chunksize;
 
     public Dictionary<Vector3, WorldGenerator.TerrainChunk> WorldDataDictionairy = new 
     Dictionary<Vector3, WorldGenerator.TerrainChunk>();
 }

T$$anonymous$$s is the function i nuse to save t$$anonymous$$s data:

     //worldgenerator -> worlddata -> file
     public void SaveWorld()
     {
         var worldgenerator = 
         GameObject.FindObjectOfType<WorldGenerator> 
         ().GetComponent<WorldGenerator>();
 
         WorldData worlddata = new WorldData();
 
         worlddata.worldname = worldgenerator.worldname;
         worlddata.chunksize = worldgenerator.chunksize;
         worlddata.chunkrenderdistance = 
         worldgenerator.chunkrenderdistance;
         worlddata.octaves = worldgenerator.octaves;
         worlddata.zoom = worldgenerator.zoom;
         worlddata.noisetype = worldgenerator.noisetype;
         worlddata.smoot$$anonymous$$ng = worldgenerator.smoot$$anonymous$$ng;
         worlddata.WorldDataDictionairy = 
         worldgenerator.currentWorldChunksGenerated;
 
         BinaryFormatter bf = new BinaryFormatter();
         FileStream file = File.Create(Application.persistentDataPath + "/" + 
         worlddata.worldname + ".world");
         bf.Serialize(file, worlddata);
         file.Close();
     }

t$$anonymous$$s is the function i use to load t$$anonymous$$s data:

     //file -> worlddata -> worldgenerator
     public void LoadWorld()
     {
         var worldgenerator = 
         GameObject.FindObjectOfType<WorldGenerator> 
         ().GetComponent<WorldGenerator>();
 
         WorldData worlddata = new WorldData();
 
         BinaryFormatter bf = new BinaryFormatter();
         if(System.IO.File.Exists(Application.persistentDataPath + "/" + 
         DropDownLabel.text + ".world"))
         {
             FileStream file = File.OpenRead(Application.persistentDataPath + 
             "/" + DropDownLabel.text + ".world");
             if(file != null)
             {
                 worlddata = (WorldData)bf.Deserialize(file);
                 file.Close();
             }
         }
 
 
         worldgenerator.worldname = worlddata.worldname;
         worldgenerator.chunksize = worlddata.chunksize;
         worldgenerator.chunkrenderdistance = 
         worlddata.chunkrenderdistance;
         worldgenerator.octaves = worlddata.octaves;
         worldgenerator.zoom = worlddata.zoom;
         worldgenerator.noisetype = worlddata.noisetype;
         worldgenerator.smoot$$anonymous$$ng = worlddata.smoot$$anonymous$$ng;
         worldgenerator.currentWorldChunksGenerated = 
         worlddata.WorldDataDictionairy;
     }