3,5-dichloro-2-hydroxy-benzaldehyde), C(7)H(4)Cl(2)O(2), crystallizes as discrete mol-ecules, the conformation of which may be influenced by an intra-molecular hydr-oxy-carbonyl O-H⋯O hydrogen bond.
An artificial neural network (ANN) was applied for the determination of V(V) based on immobilized fatty hydroxamic acid (FHA) in poly(methyl methacrylate) (PMMA). Spectra obtained from the V(V)-FHA complex at single wavelengths was used as the input data for the ANN. The V(V)-FHA complex shows a limited linear dynamic range of V(V) concentration of 10 - 100 mg/ L. After training with ANN, the linear dynamic range was extended with low calibration error. A three layer feed forward neural network using backpropagation (BP) algorithm was employed in this study. The input layer consisted of single neurons, 30 neurons in hidden a layer and one output neuron was found appropriate for the multivariate calibration used. The network were trained up to 10000 epochs with 0.003 % learning rate. This reagent also provided a good analytical pedormance with reproducibility characters of the method yielding relative standard deviation (RSD) of 9.29% and 7.09% for V(V) at concentrations of 50 mg/ L and 200 mg/ L, respectively. The limit of detection of the method was 8.4 mg/ L.
The cation of the title compound, C(7)H(13)ClN(+)·Cl(-), forms a linear hydrogen bond to the chloride anion. The cation is disordered about a mirror plane.
The low-temperature structure of the title compound, C(4)H(8)N(2)O, is ordered, whereas the central methyl-ene groups is disordered in the reported room-temperature structure. The molecule lies across a mirror plane; adjacent mol-ecules are linked by an N-H⋯O hydrogen bond into a chain.
The hydroxyl group in each of the two independent mol-ecules of the title compound, C(7)H(5)NO(4), participates in two O-H⋯O hydrogen bonds, viz. one intra-molecular bond to the nitro group and one inter-molecular bond to the aldehyde group of the same mol-ecule in the next unit, resulting in a linear chain structure. The dihedral angle between the aromatic ring and the nitro group is 10.9 (3)° in one mol-ecule and 9.9 (2)° in the other.