What is the Ketcher file structure for a chemical reaction?

The Ketcher file structure for a chemical reaction is an extension of the Ketcher file structure for a molecule. Additional molecule objects are added as reactants, reagents, solvents, and products of the reaction.

A long arrow is also added to separate reactants, reagents, solvents, and products using the following simple rules:

• Reactants - All molecules located on the left side of the arrow are considered as reactants.
• Reagents - All molecules located directly above the arrow are considered as reagents.
• Solvents - All molecules located directly below the arrow are considered as solvents.
• Products - All molecules located on the right side of the arrow are considered as products.

Plus signs are also added between reactants and between products, if there are multiples.

Here is a Ketcher file representing a simple chemical reaction with 2 reactants and 2 products:

{
    "root": {
        "nodes": [
            { "$ref": "mol0" },
            { "$ref": "mol1" },
            { "$ref": "mol2" },
            { "$ref": "mol3" },
            {
                "type": "arrow",
                "data": {
                    "mode": "open-angle",
                    "pos": [
                        { "x": 3, "y": 0, "z": 0 },
                        { "x": 4, "y": 0, "z": 0 }
                    ]
                }
            },
            {
                "type": "plus",
                "location": [ 0, 0, 0 ]
            },
            {
                "type": "plus",
                "location": [ 7, 0, 0 ]
            }
        ]
    },
    "mol0": {
        "type": "molecule",
        "atoms": [
            {
                "label": "Cl",
                "location": [ -1, 0, 0 ]
            }
        ]
    },
    "mol1": {
        "type": "molecule",
        "atoms": [
            {
                "label": "Na",
                "location": [ 1, 0, 0 ]
            },
            {
                "label": "O",
                "location": [ 2, 0, 0 ]
            }
        ],
        "bonds": [
            {
                "type": 1,
                "atoms": [ 0, 1 ]
            }
        ]
    },
    "mol2": {
        "type": "molecule",
        "atoms": [
            {
                "label": "Na",
                "location": [ 5, 0, 0 ]
            },
            {
                "label": "Cl",
                "location": [ 6, 0, 0 ]
            }
        ],
        "bonds": [
            {
                "type": 1,
                "atoms": [ 0, 1 ]
            }
        ]
    },
    "mol3": {
        "type": "molecule",
        "atoms": [
            {
                "label": "O",
                "location": [ 8.5, 0, 0 ]
            }
        ]
    }
}

⇒ One Molecule with Disconnected Parts

⇐ Adding Text Labels in Ketcher File

⇑ Ketcher File Format for Chemical Structures

⇑⇑ Ketcher - Chemical Structure Editor