Zwitterionic and biradicaloid heteroatomic cyclopentane derivatives containing different group 15 elements

Abstract

The formal cyclopentane-1,3-diyl derivatives [E1(μ-NTer)2({E2C} = NDmp)] (Ter = 2,6-dimesityl-phenyl, Dmp = 2,6-dimethylphenyl) were prepared by 1,1-insertion of CNDmp into the N–E2 bond of [E1(μ-NTer)2E2] (E1 = N, P; E2 = P, As).

The Niecke Biradicals and Their Congeners – The Journey from Stable Biradicaloids to Their Utilization for the Design of Nonlinear Optical Properties

“…For the Ito‐compounds similar E (ST) energy gaps were observed (unpublished results), the here recorded one (Table , last entry) is comparable to the Niecke‐type with R(P) = TMP/TMP, R(C) = H/ H. The Schulz‐type biradicaloid (ca. 29 kcal/mol) is more singlet stable than the Niecke‐type compound (see Table ), in accordance with previous findings . The fact that the S‐T energy separations for the Niecke, Ito, rsp.…”

“…The phosphorus congeners Ia(P) are hitherto unknown, these possess S‐T energy separations similar in magnitude as the 1,3‐diphospha‐cyclobutane‐diyl‐1,3 system, which were discussed in detail before. A peculiarity is presented by the species of type II , which were experimentally prepared by the group of Schulz and summarized in a recent reports . For the latter category interesting calculations appeared, the reader may be referred to this pertinent discussion .…”

Arsenic‐Mediated C−C Coupling of Cyanides Leading to Cyanido Arsazolide [AsC4N4]−

“…While a few cationic diazarsenium ( A d (As−N)=1.763, B 1.803–1.814 Å) and neutral tetrazaarsole ( d (As−N)=1.784–1.805 Å) heterocycles are known (Scheme , species A – C ), anionic diazarsolides are hitherto unknown. Only recently, neutral triazarsole heterocycles were isolated either by insertion of isonitriles into arsatriazanediyls [As( μ ‐NTer) 2 N] (Ter=2,6‐bis(2,4,6‐trimethylphenyl)phenyl, D d (As−N)=1.875 Å) and by making use of a [3+2] cycloaddition reaction between an arsaalkyne and an organic azide (species E d (As−N)=1.839 Å) . Arsolides of the type [R 4 C 4 As] − (R=Ph, Et) were described by Westerhausen et al .…”

“…Sr cov (As = N) = 1.74 ) [14] and C ring ÀN ring distances (1.31-1.37, Sr cov (C=N) = 1.27 ) [14] featuring partial double bond character.The first compound with an As= Nd oubleb ond (d(As-N) = 1.714(7) and 1.745 (7) )w as N,N'bis(2,4,6-tri-tert-butylphenyl)amino-iminoarsane, prepared by Lappert et al in 1986. Only recently,n eutral triazarsole heterocycles were isolated either by insertion of isonitriles into arsatriazanediyls [As(m-NTer) 2 N] (Ter = 2,6-bis(2,4,6-trimethylphenyl)phenyl, D d(AsÀN) = 1.875 ) [21] and by making use of a[ 3 + +2] cycloaddition reaction between an arsaalkyne and an organic azide (species E d(AsÀN) = 1.839 ). Only recently,n eutral triazarsole heterocycles were isolated either by insertion of isonitriles into arsatriazanediyls [As(m-NTer) 2 N] (Ter = 2,6-bis(2,4,6-trimethylphenyl)phenyl, D d(AsÀN) = 1.875 ) [21] and by making use of a[ 3 + +2] cycloaddition reaction between an arsaalkyne and an organic azide (species E d(AsÀN) = 1.839 ).…”

Cycloaddition of Alkenes and Alkynes to the P‐centered Singlet Biradical [P(μ‐NTer)]2

“…[P(μ‐NTer)] 2 is a thermally very robust biradical which can be generated in very good yields by reducing [ClP(μ‐NTer)] 2 with magnesium turnings. With [P(μ‐NTer)] 2 in hands, we studied its reactivity towards molecules bearing single, double and triple bonds , , , . We also succeeded in preparing and isolate the arsenic homologue [As( μ ‐NTer)] 2 as well as the mixed arsenic–phosphorus‐centred biradical [P( μ ‐NTer) 2 As] .…”