rdkit.Chem.rdmolfiles.MolToMolFile(NoneType, str)

I am trying to convert smi to sdf format using rdkit python library. I am running following line of python code.

def convertir_smi_sdf(file_smi):
    leer = [i for i in open(file_smi)]
    print(f"Total de smi: {len(leer)}")
    cont = 0
    cont_tot = []
    for i in leer:
        nom_mol = i.split()[1]
        smi_mol = i.split()[0]
        mol_smi = Chem.MolFromSmiles(smi_mol)
        Chem.MolToMolFile(mol_smi, f'{nom_mol}.sdf')
        cont += 1
        cont_tot.append(cont)
    print(f"Se ha convertido {cont_tot[-1]} smiles a SDF")

Any help is highly appreciated

I need this to separate this smiles format in distints sdf archives.

Error:

Output:

These kinds of errors always mean one thing: The SMILES you're inputting is invalid. In your case, you're getting the error because of the SMILES string Cl[Pt](Cl)([NH4])[NH4] which is invalid. See its picture below. Both Nitrogen atoms are forming 5 bonds without any positive charge on them.

When you parse it in RdKit, you'll get a warning like this:

To deal with this, either fix this SMILES manually or ignore it completely. To ignore it, just pass the argument sanitize=False as below:

mol_smi = Chem.MolFromSmiles(smi_mol, sanitize=False)

Just a warning: by adding sanitize=False, you'll be ignoring all the invalid SMILES.