Science. 1995 Feb 17;267(5200):999-1001. doi: 10.1126/science.267.5200.999.
Ion chromatography studies were performed to assess various models proposed for the structure of M(8)C(12) species, the met-cars. A laser desorption source was used to make a sequence of titanium-carbon clusters centered around Ti(8)C(12)(+). The Ti(8)C(12)(+) was determined to be a hollow cage cluster, with the dodechadron structure originally propposed termined to be a hollow cage cluster, with the dodecahedron structure originally proposed giving the best fit to experiment; cubic structures could be excluded. Collisional breakup of Ti(8)C(12)(+) yielded only Ti(7)C(12)(+) under the experimental conditions described herein, and modeling indicated that the cage structure was retained. Both Ti(8)C(11)(+) and Ti(8)C(13)(+) were made by the cluster source, and again, dodecahedral-type cage structures were consistent with experiment. The extra carbon atom in Ti(8)C(13)(+) was attached exohedrally to a single titanium atom. No evidence for an endohedral species was found.
离子色谱研究用于评估 M(8)C(12)物种（即 met-cars）结构的各种模型。采用激光解吸源制备了以 Ti(8)C(12)(+)为中心的一系列钛-碳团簇。确定 Ti(8)C(12)(+)为空心笼状簇，最初提出的十二面体结构与实验结果拟合度最好；排除了立方结构。在本文所述的实验条件下，Ti(8)C(12)(+)的碰撞断裂仅产生 Ti(7)C(12)(+)，而模拟表明笼状结构得以保留。通过团簇源制备了 Ti(8)C(11)(+)和 Ti(8)C(13)(+)，同样，十二面体笼状结构与实验结果一致。Ti(8)C(13)(+)中的额外碳原子以桥接方式连接到单个钛原子上。未发现笼内物种的证据。
