Contributions to the chemistry of halosilane adducts: XIX. Temperature dependent equilibrium between pentacoordinate and ionic tetracoordinate structures of an organochlorosilane-nitrogen base adduct. Synthesis and structural investigations of (NSi)-silicon-functional (1-(2-pyridone(2′-pyridyl)imine)methyl)silanes. The crystal and molecular structure of (NSi)-chloro(1-(2-pyridone- (2′-pyridyl)imine)methyl)dimethylsilane, (NSi)-(1-(2- pyridone(2′-pyridyl)imine)methyl)trichlorosilane and 1-methyl-2-(2′-pyridyl)aminopyridinium chloride