Abstract
The title compounds, K(+)·C7H7BF3O(-), (I), and K(+)·C6H4BF4 (-), (II), are mol-ecular salts containing para-substituted phenyl-tri-fluorido-borate anions. In each compound, the B atom adopts a distorted tetra-hedral BCF3 geometry. Despite their different compositions and space groups, the irregular KF8 coordination polyhedra of the potassium cations in the structures are almost identical. These polyhedra share faces and edges, generating infinite (010) layers in (I) and infinite (001) layers in (II). In (I), adjacent layers are stacked in an AAA… fashion, whereas in (II), they are stacked in an ABAB… sequence.