Department of Chemistry, University at Albany, 1400 Washington Avenue, Albany, New York 12222, USA.
Inorg Chem. 2010 Feb 15;49(4):1626-33. doi: 10.1021/ic9020367.
The first example of a reversible [Cu(4)] <--> [Cu(6)] interconversion for polynuclear copper(I) complexes under controlled experimental settings is reported. It illustrates the key role of specific crystal growth conditions for accessing the target cluster nuclearity that consequently determines physical properties of the resulting solid state products. Thus, when copper(I) benzoate crystallizes from a 1,2-dichlorobenzene solution at room temperature, it forms [Cu(4)]-core based crystalline material, [Cu(4)(O(2)CC(6)H(5))(4)] (1). In contrast, crystal growth by deposition from the gas phase at elevated temperatures results in the exclusive formation of [Cu(6)(O(2)CC(6)H(5))(6)] (2). Complexes 1 and 2 have been isolated in pure form, fully characterized, and reversibly interconverted into each other. The effect of a core structure on the spectroscopic properties of 1 and 2, such as IR, Raman, and photoluminescence, has been investigated. Additionally, a combination of X-ray powder and single crystal diffraction methods has been used to discover the temperature induced phase transition in the hexanuclear copper(I) system. Two modifications of 2 exhibiting slightly different solid state packing of the [Cu(6)(O(2)CC(6)H(5))(6)] units have been identified at room and low temperature. Moreover, reversible single-crystal-to-single-crystal transitions between these polymorphic forms have been confirmed. The important role of weak intermolecular interactions between polynuclear copper(I) units in the solid state has also been revealed and discussed.
首例在可控实验条件下实现多核铜（I）配合物中[Cu(4)]<-->[Cu(6)]可逆转变的例子被报道。它说明了特定晶体生长条件对于获得目标簇核性的关键作用，而这反过来又决定了所得固态产物的物理性质。因此，当苯甲酸铜从 1,2-二氯苯溶液在室温下结晶时，它形成了基于[Cu(4)]-核的结晶材料Cu(4)(O2CC6H5)4。相比之下，在高温下通过气相沉积进行晶体生长则导致Cu(6)(O2CC6H5)6的唯一形成。配合物 1 和 2 已被分离出纯品，进行了全面表征，并可相互可逆转化。研究了核心结构对 1 和 2 的光谱性质（如 IR、Raman 和光致发光）的影响。此外，还结合使用了 X 射线粉末和单晶衍射方法来发现六核铜（I）体系中的温度诱导相变。在室温下和低温下，发现了 2 具有略微不同的[Cu(6)(O2CC6H5)6]单元固态堆积方式的两种 2 的修饰体。此外，还证实了这些多晶形式之间的可逆单晶到单晶的转变。还揭示并讨论了弱分子间相互作用在固态中对多核铜（I）单元的重要作用。
