We have synthesized a completely new family of acyclic trimeric cyclodiphosphazane compounds comprising NH, NiPr, NtBu and NPh bridging groups. In addition, the first NH-bridged acyclic dimeric cyclophosphazane has been produced. The trimeric species display highly tuneable characteristics so that the distance between the terminal N(H)R moieties can be readily modulated by the steric bulk present in the bridging groups (ranging from ≈6 to ≈10 Å). Moreover, these species exhibit pronounced topological changes when a weak non-bonding NH⋅⋅⋅π aryl interaction is introduced. Finally, the NH-bridged chloride binding affinities have been calculated and benchmarked along with the existing experimental data available for monomeric cyclodiphosphazanes. Our results underscore these species as promising hydrogen bond donors for supramolecular host–guest applications. © 2020 Wiley-VCH GmbH

Rakesh Ganguly

SNU Management

Shi X.

León F.

Sim Y.

Quek S.

Hum G.

Khoo Y.X.J.

Ng Z.X.

Par M.Y.

Ong H.C.

Singh V.K.

<p>Shiv Nadar University is a comprehensive, multidisciplinary, research-focused, and student-centric University offering a full range of academic programs at the undergraduate, postgraduate and doctoral level. With state-of-the-art infrastructure, the University comprises of academic wings, sophisticated labs, international standard sports facilities, amphitheaters, auditorium, conference rooms and smart classrooms. The University&rsquo;s goal is to become internationally recognized for the quality of its research and creative endeavors and their applicability to improving quality of life, generating new insights and expanding the boundaries of human knowledge creativity. Committed to excellence in teaching, research and service, the University aims to serve the higher education needs of India and the world beyond.</p>

Shiv Nadar University

Angewandte Chemie - International Edition

Inorganic macrocycles remain largely underdeveloped compared with their organic counterparts due to the challenges involved in their synthesis. Among them, cyclodiphosphazane macrocycles have shown to be promising candidates for supramolecular chemistry applications due to their ability to encapsulate small molecules or ions within their cavities. However, further developments have been handicapped by the lack of synthetic routes to high-order cyclodiphosphazane macrocycles. Moreover, current approaches allow little control over the size of the macrocycles formed. Here we report the synthesis of high-order oxygen-bridged phosphazane macrocycles via a “3 + n cyclisation” (n = 1 and 3). Using this method, an all-PIII high-order hexameric cyclodiphosphazane macrocycle was isolated, displaying a larger macrocyclic cavity than comparable organic crown-ethers. Our approach demonstrates that increasing building block complexity enables precise control over macrocycle size, which will not only generate future developments in both the phosphazane and main group chemistry but also in the fields of supramolecular chemistry. © 2021, The Author(s).

Fulltext

Communications Chemistry

Size-control in the synthesis of oxo-bridged phosphazane macrocycles via a modular addition approach

Angewandte Chemie International Edition

Guest Binding via N−H⋅⋅⋅π Bonding and Kinetic Entrapment by an Inorganic Macrocycle

Angewandte Chemie

Journal of the American Chemical Society

Tailoring the Binding Properties of Phosphazane Anion Receptors and Transporters

Chemistry - A European Journal

Designing the Macrocyclic Dimension in Main Group Chemistry

New Journal of Chemistry

Hydrogen-bonding cyclodiphosphazanes: superior effects of 3,5-(CF3)2-substitution in anion-recognition and counter-ion catalysis

N-Bridged Acyclic Trimeric Poly-Cyclodiphosphazanes: Highly Tuneable Cyclodiphosphazane Building Blocks