Novel Ditopic Receptors Based on the P2N2 Diphosphazane Ring: Synthesis and X-ray Structural Characterization of Cis and Trans Bis(crown ether) Annellated 1,3,2λ54λ5-Diazadiphosphetidine 2,4-Disulfide

Article abstract of DOI:10.1021/ja00200a036

The 1,3,2,4-diazadiphosphetidine ring is used for the construction of the bis(crown ether) derivative 1, which occurs as cis and trans isomers.Refluxing triethylene glycol dianilino ether 3 with hexamethylphosphorous triamide (HMPT) in toluene followed by addition of sulfur gave 1 as a crystalline material in isolated yields ranging from 25percent to 73percent.The compounds have been characterized by a combination of 1H, 13C, and 31P NMR and mass spectral data.The structural assignments of the two diastereoisomers are based on X-ray structural analysis.Crystal data at 291 K are as follows: cis-1*H2O a=11.030(9) Angstroem, b=11.169(3) Angstroem, c=18.101(13) Angstroem, α=85.68(4) deg, β=87.06(6) deg, γ=86.57(4) deg, Z=2, triclinic, space group <*>, R=0.087 for 5888 reflections with I>/=2.5?(I); trans-1*2CH2Cl2 a=11.757(3) Angstroem, b=11.140(4) Angstroem, c=9.393(1) Angstroem, α=65.51(2) deg, β=101.12(2) deg, γ=100.63(3) deg, Z=1, triclinic, space group <*>, R=0.054 for 3531 reflections with I>/=2.5?(I).In the cis isomer, a water molecule is encapsulated in the cavity formed by the two macrocyclic moieties facing each other.The trans isomer, which crystallizes with two dichloromethane molecules, lies on a crystallographic center of symmetry.The macrocyclic intermediate precursor 4 is characterized together with the bis(crown) derivative 5.The tervalent parent compounds are extremely sensitive to moisture.The macrocycle 8 containing a P(O)H fragment is a degradation product.