In this research, ۱۰ new N-carbonyl phosphoric triamides with general formula [XC(O)NH]P(O)Y۲ (X = C۶F۵ and Y۲ = C۳H۸N۲ (۱) or Y = C۴H۱۰N (۲), C۷H۱۴N (۳), C۸H۱۶N (۴), C۸H۱۰N (۵), C۱۴H۱۴N (۶), C۴H۸NO (۷), or X = ۴-NO۲-C۶H۴ and Y = C۱۴H۱۴N (۸), C۳H۶N (۹) and C۷H۸N (۱۰)) were synthesized. Furthermore, the (C۶H۱۱NH)۳PO phosphoric triamide was synthesized and used as oxygen-donor ligand in a reaction with Iron (III) cation to preparation of a new complex, [Fe(PO(NHC۶H۱۱)۳)۳(NO۳)۲]NO۳.۲(C۳H۶O) (۱۱). Characterization was done by X-ray crystallography, IR, ۱HNMR, ۱۳CNMR, ۳۱PNMR and ۱۹FNMR spectroscopy. The following results were obtained from spectral and structural studies: (۱) The lone pair…π interactions (C═O…π and P═O…π) were studied, for the first time, on carbonylphosphoric triamides, considering new structures and their analogous structures deposited in the Cambridge Structural Database (CSD). Moreover, the orientation of C═O group toward aromatic ring was considered. Eight structures include C═O…π interaction and the carbonyl group is stacked on the ring plane in two ones, in five structures, the carbonyl group takes an angular approach towards the ring and in one structure the carbonyl oxygen approach aheads directly into the ring plane. Fifty N-carbonylphosphoric triamide structures include the P═O…π interaction. The P═O…H—N, C═O…H—N and C—H…F hydrogen bonds and C—H…π interactions were also investigated in new phosphoric triamides. A comparison of N—H…O═P hydrogen bond in new structures and analogous C(O)NHP(O)-based phosphoric triamides from CSD showed that the N…O distances in ۳, ۴ and ۶ (ranging from ۲.۷۰ – ۲.۷۵ Å) lie in the region of shortest N…O distances found (about ۵% of the total values). This is due to the electronic effect caused by the C۶F۵ group. This electronic nature also leads to nearly short C═O bonds. Furthermore, the H atom of C۶F۵C(O)NHP(O) part has a relatively high acidity character in comparison to analogous C۶H۵C(O)NHP(O) containing compounds and is suitable in formation of relatively strong hydrogen bond. (۲) In the crystal structure of compound ۱, carbonyl group does not take part in hydrogen bonding, while phosphoryl group acts as a double hydrogen bond acceptor. This leads to a new hydrogen bond pattern, including cyclic motifs (۱۰), which has not been found in any C(O)NHP(O)-based phosphoric triamides, so far. (۳) In P(O)[NR۱R۲][NR۳R۴][NR۵R۶] phosphoric triamides, the bond angles at the nitrogen atoms were analyzed and compared with the ones for RC(O)NHP(O)[NR۱R۲]۲ phosphoric triamides. It is found that the nitrogen atom of NRnRn+۱ group in the former phosphoric triamides tend to have more pyramidal environment. (۴) The relationship between the ۳۱P chemical shifts and electron-donor capabilities of groups bonded to phosphorus was studied and a good correlation was found. Keywords: C═O…π interactions, Phosphoric triamde, Hydrogen bond pattern, Spectroscopy study |
