Tetraphenylphosphonium salts of N‐thiophosphorylated thiobenzamide, mono‐thioureas or bis‐thioureas

Abstract

Reaction of the sodium salts of RC(S) NHP(S)(O‐i‐Pr)2 (R = Ph, HLI; PhNH, HLII; 2‐MeC6H4NH, HLIII; 2,6‐Me2C6H3NH, HLIV; 2,4,6‐Me3C6H2NH, HLV) or Z[NHC(S)NHP(S)(O‐i‐Pr)2]2 (Z = o‐C6H4, H2LVI; 1,2‐CH2CH2, H2LVII) with PPh4Br in 96% aqueous EtOH leads to the compounds of formulae PPh4LI–V and (PPh4)2LVI,VII. Compounds obtained were investigated by 1H and 31P{1H} NMR spectroscopy, ES mass spectrometry, and microanalysis. Recrystallization of PPh4LI from an aqueous EtOH solution (1:1, v/v) leads to the formation of PhC(S)NHP(O)(O‐i‐Pr)2 (HQ). The crystal structure of HQ reveals to be a polymorph to the previously reported structure. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:343–350, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20607

London Dispersion Forces in Crystal Packing of Thiourea Derivatives

“…The 31 P­{ 1 H} NMR spectra of the thioureas 1 – 3 and 5 in CDCl 3 each exhibit a singlet at 53.1–54.9 ppm, which is the characteristic area for neutral NTTU s (X = S). − Contrarily, the 31 P­{ 1 H} NMR spectrum of 4 in the same solvent contains a remarkably low-field shifted singlet at 57.3 ppm. This confirms the deprotonated form of NTTU s (X = S). − The 1 H NMR spectra of 1 – 5 in CDCl 3 each exhibit a unique set of signals. Particularly, the i PrO protons were found as a doublet or two doublets or a triplet for the CH 3 protons at 1.21–1.38 ppm and a doublet of septets for the CHO protons at 4.55–4.79 ppm.…”

“…In crystal engineering and growth, the (thio)­urea group is of great importance due to the combination of both hydrogen donors arising from the NH groups and the CO or CS acceptor centers. − Furthermore, modification of the (thio)­urea skeleton will make these molecules very attractive. During recent years, our efforts have been directed toward synthesis and understanding various properties of substituted thioureas of the type R 1 R 2 NC­(S)­NHP­(X)­(OR 3 ) 2 , where R 1 , R 2 = H, alkyl, aryl; R 3 = i Pr, Ph; X = O, S ( NTTU s). − We have learned that classic hydrogen bonding is crucial for both the structures and properties of NTTU s. Due to recent progress in recognizing novel noncovalent interactions, including homopolar C–H···H–C, we have recently deeply studied a novel set of thiourea derivatives RNHC­(S)­NHP­(S)­(O i Pr) 2 by applying bulky hydrophobic R differing in size and accordingly in dispersion donating properties . We have further determined that a significant amount of polar thiourea regions, NH hydrogen donors, thiocarbonyl and thiophosphoryl acceptors, together with large hydrophobic areas, leads to extraordinary stability of the systems arising from the formation of London dispersion dominated nonconventional homopolar dihydrogen C–H···H–C interactions (both intra- and intermolecular) augmented by numerous other contributors (e.g., N–H···π, N–H···S, N–H···O, C–H···S, C–H···π, π···π) …”

N‐Thiophosphorylthioureas RNHC(S)NHP(S)(OiPr)2 as an Excellent Platform for Studying the Synergy between Hydrogen‐Hydrogen Bonding and Other Families of Non‐Covalent Interactions

“…On the other hand, our group and other laboratories have performed extensive in‐depth studies of the chemistry of N ‐(thio)phosphorylated thioureas (abbreviated as NTTU s) R 1 R 2 NC(S)NHP(X)(OR 3 ) 2 . It constitutes a useful supramolecular synthon since it comprises both NH hydrogen donors, and thiocarbonyl and (thio)phosphoryl acceptors . It has been proven that it facilitates the formation of various NTTU s with intriguing architectures driven by typical hydrogen bonds …”

“…It constitutes a useful supramolecular synthon since it comprises both NH hydrogen donors, and thiocarbonyl and (thio)phosphoryl acceptors . It has been proven that it facilitates the formation of various NTTU s with intriguing architectures driven by typical hydrogen bonds …”