IAtom a4E = new Atom("Cl", new Point2d(4.598, -0.250));
a1E.setImplicitHydrogenCount(1);
a2E.setImplicitHydrogenCount(1);
acE.addAtom(a1E);
acE.addAtom(a2E);
acE.addAtom(a3E);
acE.addAtom(a4E);
acE.addBond(new Bond(a1E, a2E, CDKConstants.BONDORDER_DOUBLE));
acE.addBond(new Bond(a1E, a3E, CDKConstants.BONDORDER_SINGLE));
acE.addBond(new Bond(a2E, a4E, CDKConstants.BONDORDER_SINGLE));