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A series of the silver(I) complexes {[Ag(L)][NO3]}∞ (1), {[Ag(L)(CH3CN)][ClO4]}∞ (2), {[Ag2(L)3(CH3CN)2][PF6]2}∞ (3), and [Ag3(L)4(CH3CN)4][BF4]3 (4) [where L = N,N′‐di(2‐pyridyl)oxamide] have been prepared by the reactions of AgX (X = NO3−, ClO4−, PF6− and BF4−) with L. All the complexes have been structurally characterized by X‐ray crystallography, confirming that 1−3 are coordination polymers whereas 4 is a trinuclear complex. Complex 1 forms helical chains which are interlinked through a series of Ag···O interactions and C−H···O hydrogen bonds. In complexes 2 and 3, a new set of interactions involving two Ag···O interactions and self‐complementary double N−H···O hydrogen bonds were found to link the linear chains and ladder structures into polymer pairs (for 2) and molecular sheets (for 3). In complex 4, the molecules are interlinked by extensive Ag···N interactions and π−π stacking interactions to form molecular bands. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

A series of Zn(II) complexes with N,N 0 -di(4-pyridyl)adipoamide ligands, {[ZnX 2 (L)]$H 2 O} N (X ¼ Cl, 1, Br, 2 and I, 3; L ¼ N,N 0 -di(4-pyridyl)adipoamide), [Zn 2 X 4 (L) 2 ]$2DMF (X ¼ Cl, 4 and Br, 5) and [Zn 2 I 4 (L) 2 ]$4DMF$C 4 H 10 O, 6, were prepared and their structures determined by X-ray crystallography. Complexes 1 and 2 form double-stranded helical chains which are supported by the N-H/O and O-H/X hydrogen bonds involving the guest water molecules and the halide anions, whereas 3 shows sinusoidal chains which are interlinked by the N-H/O hydrogen bonds and p-p interactions. Complexes 1-3 represent a unique example that the halide anions show significant effect on folding and unfolding of the Zn(II) double-stranded helical coordination polymers. Complexes 1-3 can be transformed to the corresponding complexes 4-6, which are dinuclear with 34-membered metallocycles. In these complexes, the chloride and bromide anions play the same role in the crystal structures, while the iodide anion is distinct.

In this study, a rapid and sensitive method is described for the catecholamines detection in rat brain. CE with LIF detection for the determination of FITC derivatized catecholamines (dopamine, epinephrine, and norepinephrine) was demonstrated. Conventional water bath and microwave-assisted derivatization methods were employed and a significant reduction in the derivatization time from 2 h for the conventional water bath at room temperature (ca. 25°C) to 2 min for the microwave-assisted derivatization was achieved. Online sample concentration of field-amplified sample stacking (FASS) method was employed to achieve higher sensitivities (the detection limits obtained in the normal injection mode ranged from 2.6 to 4.5 ng L⁻¹ and in the FASS mode ranged from 22 to 34 pg L⁻¹). Furthermore, this microwave-assisted derivatization CE-LIF method successfully determined catecholamines in rat brain with as low as 100 ng L⁻¹ (FASS mode) to 10 μg L⁻¹ (normal injection mode). This CE-LIF method provided better detection ability when compared to the best reports on catecholamines analyses.

An unusual iridium complex, [(dfpbo)(2)Ir](2) [dfpbo = 2-(3,5-difluorophenyl)benzoxazolato-N,C(2')], which is the first dimeric iridium complex composed of two bis-cyclometalated Ir(II) structures connected by an unsupported Ir(II)-Ir(II) bond, has been synthesized and fully characterized. Under mild conditions of neutral pH at room temperature, this complex dissociated spontaneously to form the stable radical [Ir(dfpbo)(2)]*.

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