Three-dimensional hierarchical Pb-infinite coordination polymer (Pb-ICP) pompon-like microstructures with high degree of uniformity were prepared from Pb2+ ions and bi-carboxylic acid organic linker by precipitation and hydrothermal methods. Our bottom-up process revealed the direct assembly of nanosheets with 70 nm thickness to give pompon-like structure without the addition of any surfactants. Reaction parameters are critical to size and shape control and structural uniformity of the Pb-ICP nanostructures. The morphology could be tuned by adjusting the time and the reaction procedures. Based on the result of a series of comparative experiments, it was concluded that the possible formation mechanism of the pompon-like microspheres is through the intertwined nanosheets self-assembly. Photoluminescence spectroscopy shows the quenching of emission peaks of the bi-carboxylic acid linker after coordination to Pb2+ ion. Ligand-free PbO nanoflakes with a mean diameter of 40 nm were simply obtained by calcination of pompon-like Pb-ICP at 500 degrees C for 2 h under static air. The well crystallized PbO nanoflakes exhibit large band gap due to quantum confinement effect. (C) 2018 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.