Synthesis and Structural Characterization of a New Class of Macrocycles Based on a Cyclodiphosphazane Skeleton

Abstract

The novel macrocyclic compounds {(OCH2CMe2CH2O)[(S)PN-t-Bu]2}2 (4) and {(OCH2CMe2CH2O)[P(N-t-Bu)2P(1,2-O2C6Cl4)]}2·3C6H5CH3 (5·3C6H5CH3) based on the cyclodiphosphazane unit are synthesized and characterized by X-ray structure determination; their solution state NMR spectra are consistent with the solid state structures.

Two Different Pathways in the Reduction of [(S=)PCl(μ‐NtBu)]2 with Na

“…To describe the biradicaloidn ature correctly,m ultireference CASSCF and MRCI methods were used with aug-cc-pVDZ basis sets. At wo-orbital active space CAS (2,2) with A g and A u symmetry orbitals was found to describet he biradicaloid singlet state adequately.A fter geometry optimization of the biradicaloid state at the CAS(2,2) level of theory,asingle-point, state-averagedC ASSCF(2,2)c alculation including three singlet and one triplet states wasc arriedo ut. This was followed by MRCI calculations on the lowest singlet and triplet states for each symmetry.T he resultso ft hese calculations and further details can be found in the SupportingI nformation.…”

“…The sulfur-bridged hexameric macrocycle [(m-S)P(m-NtBu) 2 P(=S)] 6 (2)i st he result of head-to-tail cyclization, whereas the biradicaloid dianion [SÀP(Cl)(m-NtBu)] 2 2À is formed by ad ifferent pathway involving reduction of the P=S bonds of 1 to PÀSb onds, as observed in the solid-state structures of [{(SÀ)ClP(m-NtBu) 2 PCl(S)}Na(Na·THF 2 )] n (3)a nd [{(SÀ)ClP(m-NtBu) 2 PCl(S)} (Na·THF) 2 ] n (4). Formulation of the (2). (c) The centroids (Ct) of the six P 2 N 2 rings constituteachair conformation.…”

Mono‐, Bi‐, Tri‐ and Tetranuclear Palladium(II), Copper(I), and Gold(I) Complexes of Morpholine‐ and N‐Methylpiperazine‐Functionalized Cyclodiphosph(III)azans, cis‐[(tBuN‐μ)2(PNC4H8X)2] (X = O, NMe)

“…Perspective views of the molecular structures of 2, 4, 7-9, 14, 15, and 18 along with the atom labeling schemes are shown in Figures 1, 2, 3, 4, 5, 6, 7, and 8. The crystallographic data and details of the structural determinations are given in Tables 1 and 2 and selected bond lengths and angles are listed in Tables 3, 4, 5,6,7,8,9, and 10.…”

“…The sulfur atom and the exo-cyclic amido substituents on the phosphorus centers are present in the cis configuration. The ring nitrogen atoms adopt near planar geometry with the sum of the bond angles around nitrogen atoms being 354.31°(N1) and [7] There are two C-H···S contacts which are somewhat shorter than the sum of the van der Waals radii (3.00 Å), [8] viz. C7-H7b···S1 (at 0.5 -x, 1.5 -y, -z): 2.97 Å, 161°; C9-H9b-S2 (at -x, 0.5 + y, 0.5 -z): 2.86 Å, 138°.…”

A mixed-valent cyclodiphosphazane: Transition metal chemistry and cis/trans isomerisation

“…[11][12][13] The dichlorocyclodiphosphazanes, cis-{ClP(μ-NR)} 2 , have been effectively explored as building blocks in the synthesis of a large range of phosphorus-nitrogen macrocycles. [14][15][16][17][18][19][20] Cyclodiphosphazanes can exist as cis and trans isomers in solution as well as in the solid state (chart 1, A and B). 2 The ring conformations of these isomers can be established by single crystal X-ray diffraction studies or by 31 P NMR data, where the cis isomers show upfield chemical shifts compared to the trans analogues.…”