Molecular structure of 2 with displacement ellipsoids at 50% and hydrogen atoms omitted for clarity. Selected bond lengths (Å) and angles (°) for 2:U1-N1, 2.265(4); U1-N2, 2.246(4); U1-N3, 2.263(3); U1-N4, 2.534(3); U1-O1, 2.156(3); O1-C25, 1.302(5); C25-C25A, 1.187(8); U1-O1-C25, 158.8(3); O1-C25-C25A, 173.8(6).