Absolute Correlations of Nuclear Spin—Spin Coupling Constants with Atomic Number. III. JX—H in Isoelectronic Series and the Lighter Elements

Abstract

The equation (J_X—H/γXγH)^½ = AZ_X+B is obeyed for the isoelectronic series BH₄^‐, CH₄, and NH₄⁺. The molecular hydrides of the first period can be considered in terms of the deviation parameters from this as suggested previously. The slope of the equation, ``A'', for an isoelectronic series is considerably greater than the line obtained from a similar correlation of the Group IV molecular hydrides. Terminal and bridge hydrogen coupling with boron in the molecule diborane is considered in terms of deviation parameters from the point for the tetrahedral species BH₄^‐. All ions and molecules considered show consistently positive deviation parameters with the s character of the X—H bond exceeding the tetrahedral value and negative deviation parameters for less s character than true tetrahedral.