Synthesis and structures of [S=(H)P(μ-NR)]2, potential building blocks for inorganic phosphorus-sulfur macrocycles.

The reactions of the chloro-phosph(iii)azane dimers [ClP(μ-NR)]2 with LiSH give the dimers [S[double bond, length as m-dash](H)P(μ-NR)]2 (), which are potential new building blocks for inorganic macrocycles of the type [{P(μ-NR)}2(μ-S)]n. NMR spectroscopic studies and DFT calculations show that the preference for the cis or trans isomers of is largely influenced by the steric demands of the R-group, with cis isomers being preferred for bulky substituents. This is an important factor in regard to applications in macrocycle synthesis since the cis arrangement is pre-organized for cyclisation.

Synthesis and Hydrolytic Studies on the Air-Stable [(4-CN-PhO)(E)P(μ-N(t)Bu)]2 (E = O, S, and Se) Cyclodiphosphazanes.

Reaction of 4-CN-PhOH with [ClP(μ-N(t)Bu)]2 (1) (2:1 ratio) in the presence of Et3N produced the functionalized cyclodiphosph(III/III)azane [(4-CN-PhO)P(μ-N(t)Bu)]2 (2). Oxidation of 2 produced cyclodiphosph(V/V)azanes [(4-CN-PhO)(E)P(μ-N(t)Bu)]2 [E = O (3), S (4), and Se (5)]. This is the first example of a series of cyclodiphosph(V/V)azane derivatives obtained from a single cyclophosph(III/III)azane precursor where all the accessible chalcogen oxidized products are air-stable over prolonged periods of time.

Macrocyclic phosphazane ligands.

Inorganic macrocycles based on P(III)–N bonded frameworks can be obtained by a series of systematic routes, many of which parallel those commonly employed in the synthesis of more well known organic relatives. Such phosph(III)azane macrocycles exhibit a broad range of coordination behaviour, and provide new organically-soluble hosts, with unique steric and electronic environments. This short review explores designed approaches to this class of macromolecule and the coordination of anionic, cationic and neutral guests, and looks to the future development of related inorganic systems of this type.

The regioselective photochemical rearrangement of alpha-[PN(t)Bu](4).

The photochemical dyotropic (two-bond shift) rearrangement of the phosphazane cage alpha-[PN(t)Bu](4) (alpha) into the isomer beta-[PN(t)Bu](4) (beta) occurs via a multi-step radical mechanism; the structures of the alpha and beta isomers are directly analogous to isovalent alpha- and beta-As(4)S(4) and P(4)S(4).

Joining the crown family; the tetrameric, O-bridged macrocycle [{P(micro-N(t)Bu)}2(micro-O)]4.

The in situ reaction of the dianion [O_P(micro-N(t)Bu)]2(2-) with the dimer [ClP(micro-N(t)Bu)]2 gives the O_bridged macrocycle [{P(micro-N(t)Bu)}2(micro-O)]4 (1), being the largest crown-like phosph(III)azane of its type to be reported and having a structure that is directly related to the ubiquitous 12-crown-4.

Synthesis and structure of the Li13 cage [[[O-P(mu-NtBu)]2Li2]3(LiCl)6Li(Cl/OnBu)0.5(thf)7], containing a [O-P(mu-NtBu)]2(2-) dianion.

The hydrolysis of [ClP(mu-NtBu)]2 with H2O-Et3N in thf, followed by in situ lithiation with nBuLi gives the Li13 cage [[[O-P(mu-NtBu)]2Li2]3(LiCl)6Li(Cl/OnBu)0.5(thf)7], containing a [O-P(mu-NtBu)]2(2-) dianion that is isoelectronic with ligands of the type [(RN)P(mu-NR)]2(2-).