PHOSPHORSUBSTITUIERTE N, N′ -DIMETHYLTHIOHARNSTOFFVERBINDUNGEN. III. UNSYMMETRISCH BISPHOSPHORYLIERTE DERIVATE

Abstract

The unsymmetrically bisphosphorylated N,N′-dimethyl thiourea derivatives, 2, 3 and 5 were synthesized and investigated by ¹H, ¹³C, ¹⁹F, and ³¹P n.m.r. spectroscopy. It is concluded from the n.m.r. investigation that there is a phosphorus-phosphorus through-space interaction in these compounds.

A single-crystal X-ray diffraction study conducted on N-( dimethylphosphino)-N′-(diphenylphos phino)-N,N′-dimethyl thiourea, 3 revealed a short non-bonding PP distance of 300 pm.

Abstraction of a fluoride ion from Ph₂P‒N(Me)‒C(:S)‒N(Me)PF₂, 2 with phosphorus pentafluoride has generated an unusual PP-bonded heterocyclic cation as a hexafluorophosphate salt, (Ph₂P‒N(Me)‒C(:S)‒N(Me)PF]⁺ PF₆ ⁻, 8.

Key Words:

• N,N′-dimethylthiourea
• intramolecular P‒P interaction
• fluoride-abstraction
• x-ray.