Abstract. This work proposes a new method to solve the credit card fraud problem. Traditionally, systems based on previous transaction data were set up to predict a new transaction. This approach provides a good solution in some situations. However, there are still many problems waiting to be solved, such as skewed data distribution, too many overlapped data, fickle-minded consumer behavior, and so on. To improve the above problems, we propose to develop a personalized system, which can prevent fraud from the initial use of credit cards. First, the questionnaireresponded transaction (QRT) data of users are collected by using an online questionnaire based on consumer behavior surveys. The data are then trained by using the support vector machines (SVMs) whereby the QRT models are developed. The QRT models are used to predict a new transaction. Results from this study show that the proposed method can effectively detect the credit card fraud.

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Two new metal complexes, {[Cd2(μ2‐H2pdc)2(H2O)8]·[Cd2(H2pdc)4(H2O)2(μ2‐Cl)2]}·2H2O (1), and [Ba2(H2pdc)4(H2O)8]·2H2O (2) (H3pdc = 3, 4‐pyrazoledicarboxylic acid), were synthesized and characterized by elemental analysis, IR spectroscopy, and single‐crystal X‐ray diffraction. The crystal structures show that compound 1 is an independent unit consisting of two discrete dinuclear complex ions [Cd2(μ2‐H2pdc)2(H2O)8]2+ cation and [Cd2(H2pdc)4(H2O)2(μ2‐Cl)2]2– anion, and the two kinds of ions are linked by hydrogen bonds and electrostatic interactions to generate a 3D supramolecular network. Complex 2 is a common dinuclear structure, which is further assembled to a 3D supramolecular network through intermolecular hydrogen bonds and π–π stacks. The hydrogen bonding interactions involving lattice water or coordinated water molecules all exist in complexes 1 and 2. Notably, three coordination modes of 3, 4‐pyrazoledicarboxylic acid were observed. The thermal and photoluminescent properties of complexes 1 and 2 in the solid state were also investigated.

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