Factors Affecting NMR Couplings

NMR tells us about what?

• · The coordination number

• · The spin of a nucleus

• · The number of ligands

• · The structure of a compound

"Satellites" appear for what kind of nucleus?

• · One with high natural abundance

• · One with low natural abundance

• · A quadrupolar nucleus

• · When you have a 2:1 ratio of a particular nucleus

When the percentage of s-character decreases, the magnitude of the M-P J-coupling ...

• · Increases

• · Decreases

• · Stays the same

In square planar complexes the lowest ¹J_M-P will be observed when the ligand trans to the metal is

• · a pi donor

• · a weak pi acceptor

• · a strong pi acceptor

• · a sigma donor

The trans influence is more important than the trans effect

• · True

• · False

In a cis isomer the magnitude of the 3 bond J-coupling will be larger than for the trans isomer.

• · True

• · False

In 2 bond J-couplings, cis-couplings are smaller than trans-couplings

• · True

• · False

T₁ relaxation stands for...

• · dipole-dipole

• · spin-spin

• · quadrupolar

• · spin-lattice

T₁ is always longer than T₂.

• · True

• · False

The electric field gradient describes

• · the spin active nuclei you have present in a system

• · how many paramagnetic species are present

• · the distribution of charge in a system

• · the number of quadrupoles you have present