Residues of chlorinated pesticides in mother\u27s milk and child\u27s serum

Uzorci mlijeka i seruma 27 hospitaliziranih dojilja iz Bjelovara i Zaboka s okolnim mjestima analizirani su na ostatke kloriranih insekticida aldrina, dieldrina, endrina, heptaklora, heptaklor epoksida, lindana i ostalih stereoizomera heksaklorcikloheksana, pp-\u27DDT-a i metabolita (pp-\u27DDE i pp-\u27DDD) i op-\u27DDT. Posebno je još analizirano 18 seruma majki i isto toliko seruma njihove djece koji su svi iz Zagreba. U uzorcima smo dokazali prisutnost samo Gama-HCH (Lindan). Alfa-HCH, pp-\u27DDE, op-\u27DDT, pp-\u27DDD i pp-\u27DDT. Koncentracije nađenih insekticida mnogo su veće u mlijeku dojilja nego u serumima. U serumima djece bilo je manje samo pp-\u27DDE i pp-\u27DDT nego u serumima njihovih majki. Uzorci seruma dojilja iz Zaboka i okolnih mjesta, hospitaliziranih u Zaboku i serumi dojilja iz Bjelovara hospitaliziranih u Zagrebu (N = 27) sadržavaju više navedenih insekticida nego uzorci seruma dojilja s područja Zagreba (N = 18).Milk samples obtained from 27 hospitalized lactating women and an equal number of sera from the same women were examined for residues of chlorinated hydrocarbon insecticides: aldrin, dieldrin, endrin, heptachlor, heptachlorepoxide, lindan and other steroisomers of hexachlorcyclohexane, pp\u27DDT and its metabolites (pp\u27-DDE, pp\u27-DDD) and op\u27-DDT. Additional 18 samples of mother\u27s sera and an equal number of their children\u27s sera were examined separately. The aim was to find out whether there is a correlation between the pesticide residues in mother\u27s serum and mother\u27s milk and in the serum of the mother and her child. The insecticides were determined according to the procedure used by the US Food and Drug Administration (4). Chlorinated hydrocarbon insecticides in the serum were examined with the method described by Wyllie and coworkers (5). In all samples only the presence of a-HCH, y-HCH, pp\u27-DDE, op\u27-DDT, pp\u27-DDD and pp\u27-DDT could be demonstrated. The concentration ratio between mother\u27s milk and serum was between 4 and 11. The concentration ratio between mother\u27s and child\u27s serum was below 1 except for pp\u27-DDE and pp\u27-DDT

<i>peri</i>-Substituted Phosphino-Phosphonium Salts: Synthesis and Reactivity

The clean reaction of 5-lithio-6-(diisopropylphosphino)­acenaphthene with dichlorophosphines RPCl₂ gives the <i>peri</i>-substituted phosphino-phosphonium salts [Acenap­(P<i>i</i>Pr₂)­(PR)]⁺Cl^– (<b>2</b>, R = Ph; <b>3</b>, R = Fc; <b>4</b>, R = NMe₂; <b>5</b>, R = <i>i</i>Pr; Acenap = acenaphthene-5,6-diyl). Their ionic structure is maintained in solution and in the solid state. The reduction of <b>2</b> and <b>3</b> with LiAlH₄ led to the formation of mixed tertiary/secondary chelating bis­(phosphines) Acenap­(P<i>i</i>Pr₂)­(PRH) (<b>6</b> and <b>7</b>), which were subsequently reacted with PtCl₂(cod) to give the complexes [(<b>6</b>)/(<b>7</b>)­PtCl₂] (<b>8</b> and <b>9</b>). Reaction of <b>2</b> and <b>3</b> with a large excess of MeOTf at elevated temperature gave the chiral 1,2-diphosphoniums [Acenap­(P<i>i</i>Pr₂)­(PRMe)]²⁺([TfO]⁻)₂ (<b>10</b> and <b>11</b>), which were reduced with LiAlH₄ to the heteroleptic bis­(phosphines) Acenap­(P<i>i</i>Pr₂)­(PRMe) (<b>12</b> and <b>13</b>); these were then reacted with [(nor)­Mo­(CO)₄] to give the complexes [(<b>12</b>)/(<b>13</b>)­Mo­(CO)₄] (<b>14</b> and <b>15</b>). The heteroleptic bis­(phosphines) <b>6</b>, <b>7</b>, <b>12</b>, and <b>13</b> display large through-space couplings (formally ⁴<i>J</i>_PP = 163–199 Hz), comparable in magnitude to ¹<i>J</i>_PP couplings observed in phosphino-phosphonium salts <b>2</b>–<b>5</b> (303–412 Hz). Single-crystal X-ray structures of <b>2</b>, <b>3</b>, <b>7</b>–<b>9</b>, <b>14</b>, and <b>15</b> are reported

<i>peri</i>-Substituted Phosphino-Phosphonium Salts: Synthesis and Reactivity

The clean reaction of 5-lithio-6-(diisopropylphosphino)­acenaphthene with dichlorophosphines RPCl₂ gives the <i>peri</i>-substituted phosphino-phosphonium salts [Acenap­(P<i>i</i>Pr₂)­(PR)]⁺Cl^– (<b>2</b>, R = Ph; <b>3</b>, R = Fc; <b>4</b>, R = NMe₂; <b>5</b>, R = <i>i</i>Pr; Acenap = acenaphthene-5,6-diyl). Their ionic structure is maintained in solution and in the solid state. The reduction of <b>2</b> and <b>3</b> with LiAlH₄ led to the formation of mixed tertiary/secondary chelating bis­(phosphines) Acenap­(P<i>i</i>Pr₂)­(PRH) (<b>6</b> and <b>7</b>), which were subsequently reacted with PtCl₂(cod) to give the complexes [(<b>6</b>)/(<b>7</b>)­PtCl₂] (<b>8</b> and <b>9</b>). Reaction of <b>2</b> and <b>3</b> with a large excess of MeOTf at elevated temperature gave the chiral 1,2-diphosphoniums [Acenap­(P<i>i</i>Pr₂)­(PRMe)]²⁺([TfO]⁻)₂ (<b>10</b> and <b>11</b>), which were reduced with LiAlH₄ to the heteroleptic bis­(phosphines) Acenap­(P<i>i</i>Pr₂)­(PRMe) (<b>12</b> and <b>13</b>); these were then reacted with [(nor)­Mo­(CO)₄] to give the complexes [(<b>12</b>)/(<b>13</b>)­Mo­(CO)₄] (<b>14</b> and <b>15</b>). The heteroleptic bis­(phosphines) <b>6</b>, <b>7</b>, <b>12</b>, and <b>13</b> display large through-space couplings (formally ⁴<i>J</i>_PP = 163–199 Hz), comparable in magnitude to ¹<i>J</i>_PP couplings observed in phosphino-phosphonium salts <b>2</b>–<b>5</b> (303–412 Hz). Single-crystal X-ray structures of <b>2</b>, <b>3</b>, <b>7</b>–<b>9</b>, <b>14</b>, and <b>15</b> are reported

CCDC 1985296: Experimental Crystal Structure Determination

Related Article: Liam J. R. McGeachie, Michael Bühl, David B. Cordes, Alexandra M. Z. Slawin, J. Derek Woollins|2021|Inorg.Chem.|||doi:10.1021/acs.inorgchem.1c0072

Synthetic, Structural, NMR, and Computational Study of a Geminally Bis(<i>peri</i>-substituted) Tridentate Phosphine and Its Chalcogenides and Transition-Metal Complexes

Coupling of two acenaphthene backbones through a phosphorus atom in a geminal fashion gives the first geminally bis­(<i>peri</i>-substituted) tridentate phosphine <b>1</b>. The rigid nature of the aromatic backbone and overall crowding of the molecule result in a rather inflexible ligand, with the three phosphorus atoms forming a relatively compact triangular cluster. Phosphine <b>1</b> displays restricted dynamics on an NMR time scale, which leads to the anisochronicity of all three phosphorus nuclei at low temperatures. Strained bis- and tris­(sulfides) <b>2</b> and <b>3</b> and the bis­(selenide) <b>4</b> have been isolated from the reaction of <b>1</b> with sulfur and selenium, respectively. These chalcogeno derivatives display pronounced in-plane and out-of-plane distortions of the aromatic backbones, indicating the limits of their angular distortions. In addition, we report metal complexes with tetrahedral [(<b>1</b>)­Cu­(MeCN)]­[BF₄] (<b>5</b>), square planar [(<b>1</b>)­PtCl]­[Cl] (<b>6</b>), trigonal bipyramidal [(<b>1</b>)­FeCl₂] (<b>7</b>), and octahedral <i>fac</i>-[(<b>1</b>)­Mo­(CO)₃] (<b>8</b>) geometries. In all of these complexes the tris­(phosphine) backbone is distorted, however to a significantly smaller extent than that in the mentioned chalcogenides <b>2</b>–<b>4</b>. Complexes <b>5</b> and <b>8</b> show fluxionality in ³¹P and ¹H NMR. All new compounds <b>1</b>–<b>8</b> were fully characterized, and their crystal structures are reported. Conclusions from dynamic NMR observations were augmented by DFT calculations

Synthetic and Structural Study of the Coordination Chemistry of a <i>peri</i>-Backbone-Supported Phosphino-Phosphonium Salt

Coordination chemistry of an acenaphthene <i>peri</i>-backbone-supported phosphino-phosphonium chloride (<b>1</b>) was investigated, revealing three distinct modes of reactivity. The reaction of <b>1</b> with Mo­(CO)₄(nor) gives the Mo(0) complex [(<b>1</b>)­Mo­(CO)₄Cl] (<b>2</b>), in which the ligand <b>1</b> exhibits monodentate coordination through the phosphine donor and the P–P bond is retained. PtCl₂(cod) reacts with the chloride and triflate salts of <b>1</b> to form a mononuclear complex [(<b>1</b>Cl)­PtCl₂] (<b>3</b>) and a binuclear complex [((<b>1</b>Cl)­PtCl)₂]­[2TfO] (<b>4</b>), respectively. In both of these complexes, the platinum center adds across the P–P bond, and subsequent chloride transfer to the phosphenium center results in phosphine-chlorophosphine bidentate coordination. [((<b>1</b>)­PdCl)₂] (<b>5</b>) was isolated from the reaction of <b>1</b> and Pd₂(dba)₃ (dba = dibenzylideneacetone). Oxidative addition to palladium(0) results in a heteroleptic phosphine bridging phosphide coordination to the Pd­(II) center. In addition, reaction of <b>1</b> with BH₃·SMe₂ leads to the bis­(borane) adduct of the corresponding mixed tertiary/secondary phosphine (<b>6</b>), with BH₃ acting as both a reducing agent and a Lewis acid. The new compounds were fully characterized, including X-ray diffraction. The ligand properties of <b>1</b> and related bonding issues are discussed with help of DFT computations

Synthetic, Structural, NMR, and Computational Study of a Geminally Bis(<i>peri</i>-substituted) Tridentate Phosphine and Its Chalcogenides and Transition-Metal Complexes

Coupling of two acenaphthene backbones through a phosphorus atom in a geminal fashion gives the first geminally bis­(<i>peri</i>-substituted) tridentate phosphine <b>1</b>. The rigid nature of the aromatic backbone and overall crowding of the molecule result in a rather inflexible ligand, with the three phosphorus atoms forming a relatively compact triangular cluster. Phosphine <b>1</b> displays restricted dynamics on an NMR time scale, which leads to the anisochronicity of all three phosphorus nuclei at low temperatures. Strained bis- and tris­(sulfides) <b>2</b> and <b>3</b> and the bis­(selenide) <b>4</b> have been isolated from the reaction of <b>1</b> with sulfur and selenium, respectively. These chalcogeno derivatives display pronounced in-plane and out-of-plane distortions of the aromatic backbones, indicating the limits of their angular distortions. In addition, we report metal complexes with tetrahedral [(<b>1</b>)­Cu­(MeCN)]­[BF₄] (<b>5</b>), square planar [(<b>1</b>)­PtCl]­[Cl] (<b>6</b>), trigonal bipyramidal [(<b>1</b>)­FeCl₂] (<b>7</b>), and octahedral <i>fac</i>-[(<b>1</b>)­Mo­(CO)₃] (<b>8</b>) geometries. In all of these complexes the tris­(phosphine) backbone is distorted, however to a significantly smaller extent than that in the mentioned chalcogenides <b>2</b>–<b>4</b>. Complexes <b>5</b> and <b>8</b> show fluxionality in ³¹P and ¹H NMR. All new compounds <b>1</b>–<b>8</b> were fully characterized, and their crystal structures are reported. Conclusions from dynamic NMR observations were augmented by DFT calculations

Sterically Crowded Tin Acenaphthenes

The synthesis of crowded <i>peri</i>-5-bromo-6-(organostannyl)­acenaphthenes is described. Reaction of 5,6-dibromoacenaphthene with 1 equiv of <i>n</i>-BuLi at −40 °C in diethyl ether followed by addition of the appropriate organotin reagent at 0 °C gave 5-bromo-6-(triphenylstannyl)­acenaphthene (<b>1</b>), 5-bromo-6-(chlorodiphenylstannyl)­acenaphthene (<b>2</b>), bis­(6-bromoacenaphthen-5-yl)­diphenylstannane (<b>3</b>), bis­(6-bromoacenaphthen-5-yl)­dibenzylstannane (<b>4</b>), bis­(6-bromoacenaphthen-5-yl)­dibutylstannane (<b>6</b>), and bis­(6-bromoacenaphthen-5-yl)­dichlorostannane (<b>7</b>) in low to medium yields (10–56%). <b>4</b> was converted into 5-iodo-6-bromoacenaphthene (<b>5</b>) by stirring overnight in the presence of a large excess of iodine. The new compounds were fully characterized spectroscopically. ¹¹⁹Sn NMR spectra suggest and interaction between the tin atoms and the neighboring peri halogen atoms. Single-crystal X-ray studies on <b>1</b>–<b>4</b> and <b>6</b>–<b>8</b> revealed Sn···X distances which are significantly less than the sum of the van der Waals radii, while DFT calculations indicate Wiberg bond indices of up to 0.11. Furthermore, there is evidence of the onset of 3c–4e bonding, though according to natural population analysis, the charge on tin is close to +2 in all compounds studied. Electrostatic interactions may thus be another important driving force for the close Br···Sn interactions, along with the small covalent (donor–acceptor) contributions

Sterically Crowded Tin Acenaphthenes

The synthesis of crowded <i>peri</i>-5-bromo-6-(organostannyl)­acenaphthenes is described. Reaction of 5,6-dibromoacenaphthene with 1 equiv of <i>n</i>-BuLi at −40 °C in diethyl ether followed by addition of the appropriate organotin reagent at 0 °C gave 5-bromo-6-(triphenylstannyl)­acenaphthene (<b>1</b>), 5-bromo-6-(chlorodiphenylstannyl)­acenaphthene (<b>2</b>), bis­(6-bromoacenaphthen-5-yl)­diphenylstannane (<b>3</b>), bis­(6-bromoacenaphthen-5-yl)­dibenzylstannane (<b>4</b>), bis­(6-bromoacenaphthen-5-yl)­dibutylstannane (<b>6</b>), and bis­(6-bromoacenaphthen-5-yl)­dichlorostannane (<b>7</b>) in low to medium yields (10–56%). <b>4</b> was converted into 5-iodo-6-bromoacenaphthene (<b>5</b>) by stirring overnight in the presence of a large excess of iodine. The new compounds were fully characterized spectroscopically. ¹¹⁹Sn NMR spectra suggest and interaction between the tin atoms and the neighboring peri halogen atoms. Single-crystal X-ray studies on <b>1</b>–<b>4</b> and <b>6</b>–<b>8</b> revealed Sn···X distances which are significantly less than the sum of the van der Waals radii, while DFT calculations indicate Wiberg bond indices of up to 0.11. Furthermore, there is evidence of the onset of 3c–4e bonding, though according to natural population analysis, the charge on tin is close to +2 in all compounds studied. Electrostatic interactions may thus be another important driving force for the close Br···Sn interactions, along with the small covalent (donor–acceptor) contributions

Correlation between the out-of-Plane Components of Magnetizability and Central Magnetic Shielding in Unsaturated Cyclic Molecules

A simple classical model of magnetic-field induced pi-electron flow is discussed, showing that the contribution to the sigma(parallel to) out-of-plane component of the virtual magnetic shielding provided by pi-ring currents, at points P along the C axis of cyclic planar unsaturated hydrocarbons C H with D-nh symmetry, in the presence of a magnetic field B-ext at right angles to the a plane, is, with good approximation, connected with the pi-electron contribution to the out-of-plane component of the magnetizability, xi(parallel to). The relationship is sigma(parallel to) (h) = (mu(0)/2 pi) (s(2) + h(2))(-3/2) xi(parallel to), where s is the distance of a C nucleus from the center of the carbon ring, and h is the distance of P from a. The ring current susceptibility, that is, the strength of the pi currents, expressed in nA/T (nano ampere per tesla) within the SI system of units, is given by partial derivative I/partial derivative B-ext = xi(parallel to)(pi s(2)), which can be used as a reliable virtual measure of magnetotropicity and relative pi-electron mobility in isoelectronic systems. Criteria for the practicality of the proposed ring current model are discussed