Transition metal chemistry of cyclodiphosphanes containing phosphine and amide-phosphine functionalities: Formation of a stable dipalladium(II) complex containing a Pd–P σ-bond.CCDC reference numbers 779798–779807. For crystallographic data in CIF or other electronic format see DOI: 10.1039/c0dt00614a

Cyclodiphosphazanes containing phosphine or phosphine plus amide functionalities {(tBuNP(OC6H4PPh2-o)}2(3), {tBuNP(OCH2CH2PPh2)}2(4), {tBuHN(tBuNP)2OC6H4PPh2-o} (5), and {tBuHN(tBuNP)2OCH2CH2PPh2} (6) were synthesized by reacting cis-{tBuNPCl}2(1) and cis-[tBuHN(tBuNP)2Cl] (2) with corresponding phosphine substituted nucleophiles. The reactions of 3and 5with excess of elemental sulfur or selenium produce the corresponding tetra and trichalcogenides, {(tBuNP(E)(OC6H4P(E)Ph2-o)}2(7, E = S; 8, E = Se) and {tBuHN(tBuNP)2OC6H4P(E)Ph2-o} (9, E = S; 10, E = Se), respectively, in quantitative yields. The reactions between 3and [Rh(COD)Cl]2or [M(COD)Cl]2(M = Pd or Pt) afford bischelated complexes [Rh(CO)Cl{tBuNP(OC6H4PPh2-o)}]2(11), and [MCl2{tBuNP(OC6H4PPh2-o)}]2(12, M = Pd; 13, M = Pt) in good yield. The 1 : 2 reaction between 3and [PdCl(η3-C3H5)]2in dichloromethane resulted initially in the formation of a tripalladium complex of the type [Pd3Cl4(η3-C3H5)2{tBuNPOC6H4PPh2}2] (14a) which readily reacts with moisture to form an interesting binuclear complex, [Cl2Pd{μ-(PPh2C6H4OP(μ-tBuN)2P(O)}(μ-Cl)Pd(OC6H4PPh2)] (14b). One of the palladium(ii) atoms forms a simple six-membered chelate ring, whereas the other palladium(ii) atom facilitates the moisture assisted cleavage of one of the endocyclic P–O bonds followed by the oxidation of P(iii) to P(v) thus forming a Pd–P σ-bond. The broken ortho-phosphine substituted phenoxide ion forms a five-membered palladacycle with the same palladium(ii) atom. Similar reaction of 5with [PdCl(η3-C3H5)]2also affords a binuclear complex [{PdCl(η3-C3H5)}tBuNH{tBuNP}2OC6H4PPh2{PdCl2}] (15) containing a PdCl2moiety which forms a six-membered chelate ring viaring-phosphorus and PPh2moieties on one side and a PdCl(η3-C3H5) fragment coordinating to amide bound phosphorus atom on the other side of the ring. Treatment of 3with four equivalents of AuCl(SMe2) produces a tetranuclear complex, [(AuCl)4{tBuNP(OC6H4PPh2)}2] (16), whereas a 1 : 3 reaction between 5and AuCl(SMe2) leads to the formation of a trinuclear complex, [tBuNH{tBuNP(AuCl)}2OC6H4P(AuCl)Ph2] (17). The crystal structures of 3, 5, 9–11and 13–17are reported. [ABSTRACT FROM AUTHOR]