330438-16-9Relevant academic research and scientific papers
Synthesis, reactivity, and computational analysis of halophosphines supported by dianionic guanidinate ligands
Brazeau, Allison L.,Haenninen, Mikko M.,Tuononen, Heikki M.,Jones, Nathan D.,Ragogna, Paul J.
experimental part, p. 5398 - 5414 (2012/05/20)
The reported chemistry and reactivity of guanidinate supported group 15 elements in the +3 oxidation state, particularly phosphorus, is limited when compared to their ubiquity in supporting metallic elements across the periodic table. We have synthesized a series of chlorophosphines utilizing homo- and heteroleptic (dianionic)guanidinates and have completed a comprehensive study of their reactivity. Most notable is the reluctancy of these four-membered rings to form the corresponding N-heterocyclic phosphenium cations, the tendency to chemically and thermally eliminate carbodiimide, and the scarcely observed ring expansion by insertion of a chloro(imino)phosphine into a P-N bond of the P-N-C-N framework. Computational analysis has provided corroborating evidence for the unwillingness of the halide abstraction reaction by demonstrating the exceptional electron acceptor properties of the target phosphenium cations and the underscoring strength of the P-X bond.
Preparation, x-ray structure, and dynamic solution behaviour of N,N′,N′-tris(2,6-diisopropylphenyl)-guanidine, and its reaction with molybdenum carbonyl
Boere,Boere,Masuda,Wolmershaeuser
, p. 1613 - 1619 (2007/10/03)
The reaction of N,N′-bis(2,6-diisopropylphenyl)carbodiimide with lithium 2,6-diisopropylanilide. quenching with water and recrystallization from heptane produces the symmetric guanidine [DipNH]2C=NDip which crystallizes in the triclinic system, space group P1, a = 10.6513(11), b = 10.8997(11), c = 16.2961(17) A, α = 80.524(12), β = 78.921(13), γ = 70.060(12)°, V = 1735.2(3) A3, Z = 2. The molecule crystallizes with three perpendicular 2,6-diisopropylphenyl groups, which surround and shield the central CN3 unit, and provide (almost) three-fold symmetry around the central atom. Its dynamic solution behaviour has been studied by VT NMR between -90 and +180°C, and is consistent with three distinct barriers to N - CAr rotation. Preliminary estimates of the Gibbs free energy of activation for the lower two barriers are 56 ± 2 and 73 ± 2 kJ mol-1. Reaction of the title compound with Mo(CO)6 in refluxing n-heptane produces [DipNH]2,C=NDip·Mo(CO)3, a complex in which Mo(CO)3 is η6-coordinated to one of the diisopropylphenyl rings.
