PHYSICAL PROPERTIES
 

¹⁸³W NMR spectroscopy is appled on polytungstates and heteropolytungstates compounds.

The recommended reference is 1M Na₂WO₄ (in D₂O at pD=9 and with an absolute frequency of Na2WO4 is 4.166387 MHz with respect to 100.00 MHz of TMS). Other standard references are WF₆ (-1121ppm or 4.161733 MHz with respect to 100.00 MHz of TMS) or W(CO)₆ (4.151888 MHz with respect to 100.00 MHz of TMS). Also see IUPAC recommendations for reporting the NMR chemical shits of all nuclei relative to the ¹H resonance of TMS (02JMR323-156).

Some interesting features of the W nucleus are:

• ¹⁸³W chemical shifts.
• Long T₁ values.

In tungsten-containing compounds the following experiments can be helpful:

• ¹H-decoupled vs ¹H-coupled ¹⁸³W spectrum.
• 2D ¹H-¹⁸³W HMQC experiment ( 87ORG938 , 93MRC58 , 94MRC235 , 98MRC807 ).
• 2D ¹⁸³W-¹⁸³W COSY ( 83JACS7059 ) and INADEQUATE ( 84JACS7677 ) experiments.
• 2D ¹³C-¹⁸³W HMQC experiment using carbon detection. Indirect detection and measurement of the difficult ¹⁸³W chemical shift by means of the ¹³C nucleus.
• 2D ³¹P-¹⁸³W HMQC experiment using phosphorus detection ( 82JMR528-47 , 86JACS5622 , 88MRC895 , 87IC2826 ).
• Intensity gain ¹H-¹⁸³W factors:

 

NOE	INEPT	Inverse INEPT	HMQC
12.9	23.7	115	2737

The Transition Metals NMR: B79HAR195, 00ENC718 .
82JACS5384
93IC5095
92DALTON1431
92IC648
92IC5316
91IC62
87IC2826
89JORG359