BPt4S4 cluster: a planar tetracoordinate boron system with three charges all at their global energy minima
Although many planar hypercoordinate boron clusters of Bn and their expanded derivatives widely exist in specific charges of their wheel-shaped ground-state structures, the planar tetracoordinate boron (ptB) as the sole central atom is seldom to be reported. Meanwhile, one system with three charges all possess planar tetracoordination hasn’t been reported to our knowledge. Here, we identified an entirely ptB cluster of BPt4S4, where the peripheral sulfur atoms are the key to maintain the whole skeleton. The most remarkable is that BPt4S4n (n= -2, -1, 0) are all confirmed to be entirely planar geometries at their global energy minima (GEM) through CALYPSO global search method. The molecular orbital analysis on the lowest energy anion of BPt4S4- suggests that it fits doubly (2π and 6σ) aromaticity. Therefore, the ptB-containing BPt4S4- cluster is expected to be captured in experiment.