Sterically encumbered tin and phosphorus peri-substituted acenaphthenes

The work in this project was supported by the Engineering and Physical Sciences Research Council (EPSRC), EaStCHEM and the University of St Andrews.A group of sterically encumbered peri-substituted acenaphthenes have been prepared, containing tin moieties at the 5,6-positions in 1 – 3 ([Acenap(SnR3)2], Acenap = acenaphthene-5,6-diyl; R3 = Ph3 ( 1 ), Me3 ( 2 ); [(Acenap)2(SnMe2)2] ( 3 )) and phosphorus functional groups at the proximal peri-positions in 4 and 5 ([Acenap(PR2)(PiPr2)] R2 = Ph2 ( 4 ), Ph(iPr) ( 5 )). Bis(stannane) structures 1 – 3 are dominated by repulsive interactions between the bulky tin groups, leading to peri-distances approaching the sum of van der Waals radii. Conversely, the quasi-linear CPh-P···P three-body fragments found in bis(phosphine) 4 suggest the presence of a lp(P)−σ*(P–C) donor–acceptor 3c-4e type interaction, supported by a notably short intramolecular P···P distance and notably large JPP through-space coupling (180 Hz). Severely strained bis(sulfides) 4-S and 5-S , experiencing pronounced in-plane and out-of-plane displacements of the exocyclic peri-bonds, have also been isolated following treatment of 4 and 5 with sulfur. The resulting nonbonded intramolecular P···P distances, ∼4.05 Å and ∼12% longer than twice the van der Waals radii of P (3.60 Å), are among the largest ever reported peri-separations, independent of the heteroatoms involved, and comparable to the distance found in 1 containing the larger Sn atoms (4.07 Å). In addition we report two metal complexes with square planar [( 4 )PtCl2] ( 4-Pt ) and octahedral cis-[( 4 )Mo(CO)4] ( 4-Mo ) geometries. In both complexes the bis(phosphine) backbone is distorted, but notably less so than in bis(sulfide) 4-S . All compounds were fully characterized, and except for bis(phosphine) 5 , crystal structures were determined.PostprintPostprintPeer reviewe

Rječnik hrvatskoga ili srpskoga jezika dovršen

Simple protocols have been devised for peroxyoxalate chemiluminescence demonstrations that use urea–hydrogen peroxide or sodium percarbonate as oxidants in place of aqueous solutions of hydrogen peroxide. The procedures described are compatible with well-known peroxyoxalates and fluorescers and have been found to be convenient for use for outreach activities in venues with limited laboratory facilities.PostprintPeer reviewe

Main Group Tellurium Heterocycles Anchored by a (P2N2)-N-V Scaffold and Their Sulfur/Selenium Analogues

A comprehensive investigation of reactions of alkali-metal derivatives of the ditelluro dianion [TePV((NBu)-Bu-t)(mu-(NBu)-Bu-t)](2)(2-) (L2-, E = Te) with p-block element halides produced a series of novel heterocycles incorporating (P2N2)-N-V rings, tellurium, and group 13-16 elements. The dianion engages in Te,Te'-chelation to the metal center in Ph2Ge and R2Sn (R = Bu-t, Bu-n, Ph) derivatives; similar behavior was noted for group 14 derivatives of L2- (E = S, Se). In the case of group 13 trihalides MCl3 (M = Ga, In), neutral spirocyclic complexes (L)M[(NBu)-Bu-t(Te)P-v(mu-(NBu)-Bu-t)(2)(PN)-N-III(H)Bu-t)] (M = Ga, In) comprised of a Te,Te'-chelated ligand L2- and a N,Te-bonded ligand resulting from loss of Te and monoprotonation were obtained. In reactions with RPCl2 (R = Bu-t, Ad, (Pr2N)-Pr-i) a significant difference was observed between Se- and S-containing systems. In the former case, Se,Se'-chelated derivatives were formed in high yields, whereas the N,S-chelated isomers predominated for sulfur. All complexes were characterized by multinudear (H-1, P-31, Se-77, Sn-119, and Te-123) NMR spectroscopy; this technique was especially useful in the analysis of the mixture of (L) (Se) and (L)(SeSe) obtained from the reaction of Se2Cl2 with L2- (E = Te). Single-crystal X-ray structures were obtained for the spirocydic In complex (9), (L)GePh2 (E = Te, 10), (L)(SnBu2)-Bu-t = Te, 12a); E = Se, 12aSe, E = S, 12aS) and (L)(mu-SeSe) (E = Te, 16)

Main Group Tellurium Heterocycles Anchored by a P₂^VN₂ Scaffold and Their Sulfur/Selenium Analogues

A comprehensive investigation of reactions of alkali-metal derivatives of the ditelluro dianion [TeP^V(N^tBu)­(μ-N^tBu)]₂^2– (<b>L</b>^2–, E = Te) with p-block element halides produced a series of novel heterocycles incorporating P₂^VN₂ rings, tellurium, and group 13–16 elements. The dianion engages in Te,Te′-chelation to the metal center in Ph₂Ge and R₂Sn (R = ^tBu, ⁿBu, Ph) derivatives; similar behavior was noted for group 14 derivatives of <b>L</b>^2– (E = S, Se). In the case of group 13 trihalides MCl₃ (M = Ga, In), neutral spirocyclic complexes (<b>L</b>)­M­[N^tBu­(Te)­P^V(μ-N^tBu)₂P^IIIN­(H)^tBu)] (M = Ga, In) comprised of a Te,Te′-chelated ligand <b>L</b>^2– and a N,Te-bonded ligand resulting from loss of Te and monoprotonation were obtained. In reactions with RPCl₂ (R = ^tBu, Ad, ⁱPr₂N) a significant difference was observed between Se- and S-containing systems. In the former case, Se,Se′-chelated derivatives were formed in high yields, whereas the N,S-chelated isomers predominated for sulfur. All complexes were characterized by multinuclear (¹H, ³¹P, ⁷⁷Se, ¹¹⁹Sn, and ¹²⁵Te) NMR spectroscopy; this technique was especially useful in the analysis of the mixture of (<b>L</b>)­(Se) and (<b>L</b>)­(SeSe) obtained from the reaction of Se₂Cl₂ with <b>L</b>^2– (E = Te). Single-crystal X-ray structures were obtained for the spirocyclic In complex (<b>9</b>), (<b>L)</b>GePh₂ (E = Te, <b>10</b>), (<b>L)</b>Sn^tBu₂ (E = Te, <b>12a</b>); E = Se, <b>12aSe</b>, E = S, <b>12aS</b>) and (<b>L</b>)­(μ-SeSe) (E = Te, <b>16</b>)

Main Group Tellurium Heterocycles Anchored by a P₂^VN₂ Scaffold and Their Sulfur/Selenium Analogues

A comprehensive investigation of reactions of alkali-metal derivatives of the ditelluro dianion [TeP^V(N^tBu)­(μ-N^tBu)]₂^2– (<b>L</b>^2–, E = Te) with p-block element halides produced a series of novel heterocycles incorporating P₂^VN₂ rings, tellurium, and group 13–16 elements. The dianion engages in Te,Te′-chelation to the metal center in Ph₂Ge and R₂Sn (R = ^tBu, ⁿBu, Ph) derivatives; similar behavior was noted for group 14 derivatives of <b>L</b>^2– (E = S, Se). In the case of group 13 trihalides MCl₃ (M = Ga, In), neutral spirocyclic complexes (<b>L</b>)­M­[N^tBu­(Te)­P^V(μ-N^tBu)₂P^IIIN­(H)^tBu)] (M = Ga, In) comprised of a Te,Te′-chelated ligand <b>L</b>^2– and a N,Te-bonded ligand resulting from loss of Te and monoprotonation were obtained. In reactions with RPCl₂ (R = ^tBu, Ad, ⁱPr₂N) a significant difference was observed between Se- and S-containing systems. In the former case, Se,Se′-chelated derivatives were formed in high yields, whereas the N,S-chelated isomers predominated for sulfur. All complexes were characterized by multinuclear (¹H, ³¹P, ⁷⁷Se, ¹¹⁹Sn, and ¹²⁵Te) NMR spectroscopy; this technique was especially useful in the analysis of the mixture of (<b>L</b>)­(Se) and (<b>L</b>)­(SeSe) obtained from the reaction of Se₂Cl₂ with <b>L</b>^2– (E = Te). Single-crystal X-ray structures were obtained for the spirocyclic In complex (<b>9</b>), (<b>L)</b>GePh₂ (E = Te, <b>10</b>), (<b>L)</b>Sn^tBu₂ (E = Te, <b>12a</b>); E = Se, <b>12aSe</b>, E = S, <b>12aS</b>) and (<b>L</b>)­(μ-SeSe) (E = Te, <b>16</b>)

Sterically Encumbered Tin and Phosphorus <i>peri-</i>Substituted Acenaphthenes

A group of sterically encumbered <i>peri</i>-substituted acenaphthenes have been prepared, containing tin moieties at the 5,6-positions in <b>1</b>–<b>3</b> ([Acenap­(SnR₃)₂], Acenap = acenaphthene-5,6-diyl; R₃ = Ph₃ (<b>1</b>), Me₃ (<b>2</b>); [(Acenap)₂(SnMe₂)₂] (<b>3</b>)) and phosphorus functional groups at the proximal <i>peri</i>-positions in <b>4</b> and <b>5</b> ([Acenap­(PR₂)­(P^<i>i</i>Pr₂)] R₂ = Ph₂ (<b>4</b>), Ph­(^<i>i</i>Pr) (<b>5</b>)). Bis­(stannane) structures <b>1</b>–<b>3</b> are dominated by repulsive interactions between the bulky tin groups, leading to <i>peri</i>-distances approaching the sum of van der Waals radii. Conversely, the <i>quasi</i>-linear C_Ph-P···P three-body fragments found in bis­(phosphine) <b>4</b> suggest the presence of a lp­(P)−σ*­(P–C) donor–acceptor 3c-4e type interaction, supported by a notably short intramolecular P···P distance and notably large <i>J</i>_PP through-space coupling (180 Hz). Severely strained bis­(sulfides) <b>4-S</b> and <b>5-S</b>, experiencing pronounced in-plane and out-of-plane displacements of the exocyclic <i>peri</i>-bonds, have also been isolated following treatment of <b>4</b> and <b>5</b> with sulfur. The resulting nonbonded intramolecular P···P distances, ∼4.05 Å and ∼12% longer than twice the van der Waals radii of P (3.60 Å), are among the largest ever reported <i>peri</i>-separations, independent of the heteroatoms involved, and comparable to the distance found in <b>1</b> containing the larger Sn atoms (4.07 Å). In addition we report two metal complexes with square planar [(<b>4</b>)­PtCl₂] (<b>4-Pt</b>) and octahedral <i>cis</i>-[(<b>4</b>)­Mo­(CO)₄] (<b>4-Mo</b>) geometries. In both complexes the bis­(phosphine) backbone is distorted, but notably less so than in bis­(sulfide) <b>4-S</b>. All compounds were fully characterized, and except for bis­(phosphine) <b>5</b>, crystal structures were determined

Sterically encumbered tin and phosphorus <i>peri</i>-substituted acenaphthenes

A group of sterically encumbered peri-substituted acenaphthenes have been prepared, containing tin moieties at the 5,6-positions in 1-3 ([Acenap(SnR )], Acenap = acenaphthene-5,6-diyl; R = Ph (1), Me (2); [(Acenap)(SnMe )] (3)) and phosphorus functional groups at the proximal peri-positions in 4 and 5 ([Acenap(PR)(PPr )] R = Ph (4), Ph(Pr) (5)). Bis(stannane) structures 1-3 are dominated by repulsive interactions between the bulky tin groups, leading to peri-distances approaching the sum of van der Waals radii. Conversely, the quasi-linear C-P⋯P three-body fragments found in bis(phosphine) 4 suggest the presence of a lp(P)-σ*(P-C) donor-acceptor 3c-4e type interaction, supported by a notably short intramolecular P⋯P distance and notably large J through-space coupling (180 Hz). Severely strained bis(sulfides) 4-S and 5-S, experiencing pronounced in-plane and out-of-plane displacements of the exocyclic peri-bonds, have also been isolated following treatment of 4 and 5 with sulfur. The resulting nonbonded intramolecular P⋯P distances, ∼4.05 Å and ∼12% longer than twice the van der Waals radii of P (3.60 Å), are among the largest ever reported peri-separations, independent of the heteroatoms involved, and comparable to the distance found in 1 containing the larger Sn atoms (4.07 Å). In addition we report two metal complexes with square planar [(4)PtCl] (4-Pt) and octahedral cis-[(4)Mo(CO)] (4-Mo) geometries. In both complexes the bis(phosphine) backbone is distorted, but notably less so than in bis(sulfide) 4-S. All compounds were fully characterized, and except for bis(phosphine) 5, crystal structures were determined