Compounds of Copper(II) and Nickel(II) with 6,8,8,13,13,15-Hexamethyl-1,2,4,5,9,12- hexaazacyclopentadeca-5,15(1)-diene and Some 3-Substituted Homologues

1998 ◽  
Vol 51 (7) ◽  
pp. 611 ◽  
Author(s):  
Neil F. Curtis ◽  
Olga P. Gladkikh ◽  
David C. Weatherburn ◽  
John S. De Courcey ◽  
T. Neil M. Waters
Keyword(s):  
Metal Ions ◽  
Ground State ◽  
Mirror Symmetry ◽  
Macrocyclic Ligand ◽  
The Other ◽  
Singlet Ground State ◽  
Triplet Ground State ◽  
Square Planar

Copper(II) and nickel(II) compounds, [M(L)]2+, of the macrocyclic ligand 6,8,8,13,13,15-hexamethyl-1,2,4,5,9,12-hexaazacyclopentadeca-5,15(1)-diene are formed by reaction of compounds of 4,4,9,9-tetramethyl-5,8-diazadodecane-2,11-dione dihydrazone with methanal. Analogous reactions with aldehydes RHCO, or ketones RR′CO, form compounds of 3-R or 3-RR′ substituted ligands, [M(r- L)]2+ or [M(rr′-L)]2+, respectively. The nickel(II) cations form singlet ground state salts, e.g. [Ni(L)]X2, X = [ClO4]- or ½[ZnCl4]2-, and also triplet ground state compounds, e.g. [Ni(L) (NCS)2] and [Ni(L)(X)] (ClO4) (X = NO2-, C2O42-, N3-, etc.). The structures of [Cu(L)] (ClO4)2, [Ni(L)] (ClO4)2, the 3-propyl compound formed from butanal, [Cu(pr-L)] (ClO4)2.H2O, and the compounds of 9,11,11,16,16,18-hexamethyl-7,8,12,15,19,20-hexaazaspiro[5.14]eicosa-8,18(1)-diene (chex-L), formed from cyclohexanone, namely [Cu(chex-L)] (ClO4)2.MeOH, [Ni(chex-L)] (ClO4)2, and [Ni(chex-L)] (ClO4)2.MeOH, were determined. All have the metal ions in tetrahedrally twisted square-planar coordination, by N1, N5, N9 and N12 , with N9N12-rac, for the (L) and (pr-L) compounds, or by the structurally equivalent N3, N7, N10 and N14, with N7N10-rac, for the (chex-L) compounds. The [Cu(L)]2+ and [Cu(pr-L)]2+cations have saddle-like macrocycle conformations, with approximate mirror symmetry, while the other compounds have ′twisted′ macrocycle conformations with approximate twofold symmetry {[Cu(L)] (ClO4)2, C15H32Cl2CuN6O8, orthorhombic,P 212121, a 8·562(7), b 13·096(8), c 20·257(6) Å, Z 4, R 0·041 for 1540 reflections; [Ni(L)] (ClO4)2, C15H32Cl2N6NiO8, orthorhombic, P21/n, a 13·500(3), b 9·207(2), c 19·478(5) Å, β 103·94(2)°, Z 4, R1 0·055 for 2650 reflections; [Cu(Pr-L)] (ClO4)2.H2O, C18H40Cl2CuN6O9, monoclinic, C 2, a 24·229(5), b 13·780(3), c 8·877(2) Å, β 108·79(3)°, Z 4, R1 0·067 for 1765 reflections; [Cu(chex-L)] (ClO4)2.MeOH, C21H44Cl2CuN6O9, monoclinic, C 2/c, a 17·086(5), b 24·539(2), c 14·496(1) Å, β 89·94(2), Z 8, R1 0·072 for 2521 reflections; [Ni(chex-L)] (ClO4)2, C20H40Cl2N6NiO8, monoclinic, P 21/c, a 14·820(2), b 18·599(4), c 10·282(1) Å, β 106·26(1)°, Z 4, R1 0·067 for 2552 reflections; [Ni(chex-L)] (ClO4)2.MeOH, C21H44Cl2CuN6O9, monoclinic, C 2/c, a 14·451(2), b 24·11(2), c 16·740(3) Å, β 90·14(1)°, Z 8, R1 0·064 for 2598 reflections}.

Studies of Some Tetraazacyclopentadecadiene Complexes of Nickel(II). The Crystal and Molecular-Structure of (1RS,8SR)-(5,7,7,13,15,15-Hexamethyl-1,4,8,12-Tetraazacyclopentadeca-4,1 2-Diene)Nickel(II) Perchlorate Hydrate

1986 ◽  
Vol 39 (10) ◽  
pp. 1509 ◽  
Author(s):  
NF Curtis ◽  
GJ Gainsford
Keyword(s):  
Molecular Structure ◽  
Ground State ◽  
Crystal And Molecular Structure ◽  
Macrocyclic Ligand ◽  
Isomeric Form ◽  
Monoclinic Space Group ◽  
Singlet Ground State ◽  
Triplet Ground State ◽  
Square Planar ◽  
Coordination Plane

The crystal and molecular structure has been determined by X-ray diffractometry for the singlet ground state nickel(II) compound of a fifteen- membered tetraaza macrocyclic ligand , formed by reaction of a mixture of tris ( ethanediamine )nickel(II) and tris (propane-1,3- diamine )nickel(II) perchlorates with acetone. The compound, (1RS,8SR)- 5,7,7,13,15,15-hexamethyl-1,4,8,12-tetraazacyclopentadeca-4,12- diene )nickel(II) perchlorate hydrate, [Ni( hmpd )](ClO4)2.H2O, is monoclinic, space group P21/C, a 1158.76(14), b 1319.53(22), c 1630.35(21) pm, β 96.209(10)°, R 0.046, Rw 0.062 for 2798 reflections. The nickel(II) ion is in tetrahedrally distorted square-planar coordination [mean Ni-N distances 188.9 pm ( imine ), 191.9 pm (amine), displacements of nitrogens c. �20 pm from mean coordination plane]. Triplet ground state compounds [Ni( hmpd )( acac )]ClO4 and [{Ni( hmpd )}2C2O4](ClO4)2, with the macrocycle in folded coordination, were prepared and converted into an isomeric form of [Ni( hmpd )](ClO4)2. The 3,5,7,7,13,15,15-heptamethyl homologue of [Ni( hmpd )]2+ was prepared by reaction of tris (propane-1,2-diamine)- and tris (propane-1,3-diamine)- nickel(II) perchlorates with acetone. The electronic (d-d), 1H N.M.R. and 13C N.M.R . spectra of compounds of these macrocyclic cations, and of (5,5,7,13,15,15-hexamethyl-1,4,8,12-tetraazacyclopentadeca-7,12-diene) nickel(II) are reported.

Nickel(II) and copper(II) complexes of the macrocyclic ligand 5,7,7-Trimethyl-1,4,8,11-tetraazacyclotetradec-4-ene

1975 ◽  
Vol 28 (2) ◽  
pp. 275 ◽  
Author(s):  
NF Curtis ◽  
TN Milestone
Keyword(s):  
Ground State ◽  
Macrocyclic Ligand ◽  
Mesityl Oxide ◽  
Singlet Ground State ◽  
Triplet Ground State ◽  
Diacetone Alcohol ◽  
Square Planar

Nickel(II) and copper(II) complexes of 1,4,8,11-tetraazaundecane, (L), react with acetone, diacetone alcohol or mesityl oxide to form complexes of the macrocyclic ligand 5,7,7-trimethyl-1,4,8,11-tetra- azacyclotetradec-4-ene. For the nickel(II) cation, singlet ground state, square planar, salts are formed with poorly coordinating anions such as tetrachlorozincate, and triplet ground state, pseudoocta- hedral compounds with coordinating anions. These occur as trans compounds (macrocycle in planar coordination) for the unidentate anions NCS-, N3- and Cl- and as cis compounds (macrocycle in folded coordination)for the chelating anions acetylacetonate and oxalate. Different configurations of the chiral nitrogen centres are optimum for planar and for folded coordination of the macrocycle.

Compounds of Nickel(II) With trans-6,13-Dinitro- and trans-6,13-diamino-6,13-dimethyl-1,4,8,11-tetraazacyclotetradecane, with Structural Studies of Five (trans-6,13-Diamino-6,13-dimethyl-1,4,8,11-tetraazacyclotetradecane)nickel(II) Compounds

1993 ◽  
Vol 46 (6) ◽  
pp. 755 ◽  
Author(s):  
NF Curtis ◽  
GJ Gainsford ◽  
A Siriwardena ◽  
DC Weatherburn
Keyword(s):  
Rate Constant ◽  
Catalytic Hydrogenation ◽  
Ground State ◽  
Macrocyclic Ligand ◽  
Singlet Ground State ◽  
Structural Studies ◽  
Nacl Solution ◽  
Triplet Ground State ◽  
Square Planar ◽  
Acid And Base

Compounds of NiII with the macrocyclic ligand trans-6,13-dimethyl-6,13-dinitro-1,4,8,11-tetraazacyclotetradecane ( dino ), which is formed by condensation of bis (ethane-1,2-diamine)nickel(II) salts, nitroethane and formaldehyde, are described, together with homologues formed by substituting propane-1,2-diamine and/or 1-nitropropane. The nitro functions of [Ni( dino )]2+ were reduced by catalytic hydrogenation to form (trans-6,13-diamino-6,13-dimethyl-1,4,8,11-tetraazacyclotetradecane)nickel(II), [Ni( diam )]2+, isolated as approximately equal amounts of two isomeric forms; designated α (with the R,S,R,S configuration of the chiral nitrogen centres, overall configuration 1α,4α,6β,8α,11α,13α), and β (with the R,R,S,S, 1α,4β,6α,8β,11α,13β configuration). The α-isomer is metastable, and in solution isomerizes to the β-isomer, with rate constant of 5.0(5)×10-5 s-1 in 2 mol l.-1. NaCl solution at 50°C, the rate of this reaction increasing in both acid and base. Protonation constants (pK at 25°C in 0.1 mol l.-1 NaClO4) for diam are 11.2(1), 9.7(1), 6.2(1), 5.3(1), and for the isomeric nickel(II) cations are α 4.94(2), 2.4(5); and β 4.5(1), 4.0(1). Compounds of diam with the β-configuration were prepared with triplet ground state NiII with diam in hexadentate coordination (e.g. β-[Ni(diam-N4)] Cln ) and in tetradentate coordination with the neutral (e.g. trans-β-[Ni(diam-N4)(NCS)2]) or diprotonated ligand (e.g. trans-β-[Ni(diamH2-N4)(NCS)2](CNS)2). Compounds prepared with the α-configuration with triplet ground-state NiII had pentadentate diam with the neutral (e.g. trans-α-[Ni(diam-N5)(H2O)]Cl2) or monoprotonated ligand (e.g. trans-α-[Ni(diamH-N5) Cl ] (ClO4)2). Singlet ground-state NiII compounds with the square planar diprotonated ligand were prepared for both configurations. Structures are reported for β-[Ni(diam-N6)](ClO4)2(H2O), R 0.062 for 5708 reflections; β-[Ni(diam-N6)] [ZnCl4].1.5H2O, R 0.064 for 4332 reflections; β-[Ni(diam-N6)]Cl2.6H2O, R 0.044 for 2001 reflections; trans-β-[Ni(diam-N4)(NCS)2] R 0.056 for 1521 reflections; and trans-α-[Ni(diamH-N5) Cl ](ClO4)2(H2O), R 0.047 for 2667 reflections.

Preparation, and complexes with nickel(II) and copper(II), of a diazepane amine alcohol. The structure of [4,4-dimethyl-7-(5,5,7-trimethyl-1,4-diazepan-1-yl)-5-azaheptan-2-ol]nickel(II) perchlorate

1983 ◽  
Vol 36 (7) ◽  
pp. 1341 ◽  
Author(s):  
KR Morgan ◽  
GJ Gainsford ◽  
NF Curtis
Keyword(s):  
Ground State ◽  
Coordination Compounds ◽  
Major Product ◽  
Boat Conformation ◽  
Singlet Ground State ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxygen Donor ◽  
Square Planar ◽  
Coordination Plane

Reduction of 4,4,12,12-tetramethyl-5,8,11-triazapentadecane-2,14-dione diperchlorate by sodium borohydride yields as the major product one isomer of 4,4-dimethyl-7-(5,5,7-trimethyl-1,2-diazepam 1-yl)-5-azaheptan-2-ol, pyaz. The coordination compounds [M(pyaz)] (ClO4), and [Ni(pyaz)(NCS)] CNS (M = NiII, CuII) were prepared, the latter being assigned five-coordinate structures. The structure of singlet ground state [Ni(pyaz)] (ClO4)2 was determined by X-ray diffraction [space group P212121, Z 4, a 1450.8(2), b 1522.2(1), c 1048.5(1) pm, R 0.0675, Rw 0.0768 for 2461 reflections]. The compound has a square-planar coordination arrangement, with the three nitrogen and the oxygen donor atoms of the pyaz ligand approximately coplanar [Ni-O 190.0(6) pm; Ni-N 192.8(6), 189.2(6), 189.2(6) pm in sequence N(5) of chain, N(l), N(4) of diazepane]. The diazepane ring adopts a boat conformation. One side of the nickel(II) coordination plane is sterically crowded by the presence of two axial methyl substituents. The ligand has two non-equivalent chiral centres (C(14) of the diazepane ring and C(2) of the amine alcohol chain), both present in the R configuration in the crystal studied. The three nitrogen atoms, which became chiral centres upon coordination, are present in the S configuration for two diazepane nitrogen atoms and in the R configuration for the 5-aza chain nitrogen.

5-Coordinate Compounds of Nickel(II) and Copper(II) With the Triamine Diimine Ligands 13-imino-4,4,6,11,11-pentamethyl-3,7,10-Triazatetradec-6-en-1-amine and 4,6,11-Triethyl-13-imino-4,11-dimethyl-3,7,10-triazapentadec-6-en-1-amine

1988 ◽  
Vol 41 (6) ◽  
pp. 957 ◽  
Author(s):  
NF Curtis
Keyword(s):  
Ground State ◽  
Metal Ion ◽  
Colour Change ◽  
Singlet Ground State ◽  
Diimine Ligands ◽  
Protonation Reaction ◽  
Square Planar ◽  
Ion Substitution ◽  
Secondary Amino ◽  
Coloured Complex

Reaction of nickel(II) with 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene diperchlorate in the presence of ammonia yields a lilac- coloured complex of nickel(II) with 13-imino-4,4,6,11,11-pentamethyl-3,7,10-triazatetradec-6-en-1-amine, a pentadentate ligand with one primary and two secondary amino, plus one primary and one secondary imino , donor groups. The copper(II) complex of the ligand was formed from the nickel(II) compound by metal-ion substitution. The cations have d-d spectra indicative of five-coordination. The complex cations undergo a reversible protonation reaction with a change from five-coordinate to square planar, with a colour change for nickel(II) from lilac (triplet ground state) to yellow (singlet ground state), and for copper(II) from blue to violet. The compounds of the homologous ligand 4,6,11-triethyl-13-imino-4,11- dimethyl-3,7,10-triazapentadec-6-en-1-amine were similarly prepared, and have similar properties.

[(1RS,4RS)-5,5,7,13,15,15-Hexamethyl-1,4,8,12-tetraazacyclopentadeca-7,12-diene-N1,N4,N8,N12]nickel(II) diperchlorate

2000 ◽  
Vol 57 (1) ◽  
pp. m48-m50 ◽  
Author(s):  
Neil F. Curtis ◽  
Joyce M. Waters ◽  
Clifton E. Rickard
Keyword(s):  
Hydrogen Bonds ◽  
Ground State ◽  
Title Compound ◽  
Molecular Clusters ◽  
Singlet Ground State ◽  
Bond Lengths ◽  
Square Planar

The title compound, [Ni(C17H34N4)](ClO4)2, has singlet ground-state nickel(II) complex cations in tetrahedrally twisted square-planar coordination by the four N atoms of the 15-membered diamine diimine tetraazamacrocycle and disordered perchlorate anions, linked into molecular clusters by N—H...O hydrogen bonds and weak Ni...O interactions. The cation has approximate twofold symmetry, with bond lengths Ni—Namineof 1.920 (2) and 1.924 (2) Å, and Ni—Nimineof 1.915 (2) and 1.929 (2) Å, andtrans–N—Ni—N angles of 165.1 (1) and 163.4 (1)°, with the shortest Ni...O distance being 3.27 (3) Å.

Compounds of Nickel(II) and Copper(II) With 3,5,5,13,13,15-Hexamethyl-1,2,6,9,12-pentaazacyclopentadeca-2,15-diene

1987 ◽  
Vol 40 (12) ◽  
pp. 1941
Author(s):  
NF Curtis ◽  
KR Morgan
Keyword(s):  
Ground State ◽  
Singlet Ground State ◽  
Amino Ketone ◽  
Triplet Ground State ◽  
Magnetic Susceptibilities ◽  
Kinetics Of ◽  
Formation Of Complexes

Reaction of the bis-β-amino ketone 4,4,12,12-tetramethyl-5,8,11-triazapentadecane-2,14-dione diperchlorate with nickel(II) or copper(II) in the presence of hydrazine results in the formation of complexes of the tetradentate pentaaza macrocycle 3,5,5,13,13,15-hexamethyl-1,2,6,9,12-pentaazacyclopentadeca-2,15-diene hpd. Singlet ground state [Ni( hpd )] (ClO4)2, triplet ground state [Ni( hpd )(NCS)2], [Ni( hpd )A] ClO4 (A = acac -, 1/2(C2O42-), NO2-1,[Ni( hpd )(NO3)] NO3 and [Cu( hpd )](C1O4)2 were prepared. Infrared, electronic, 1H and 13C n.m.r. spectra, magnetic susceptibilities, and the kinetics of the slow acid promoted aquation reactions of the cations at 25�C in HCl/NaCl solutions (I= 1 mol 1-1) are reported.

Density Functional Theory on NV Center in 4H SiC

2017 ◽  
Vol 897 ◽  
pp. 269-274 ◽  
Author(s):  
András Csóré ◽  
Ádám Gali
Keyword(s):  
Density Functional Theory ◽  
Ground State ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Vacancy Defect ◽  
The Other ◽  
Nitrogen Vacancy ◽  
Functional Theory ◽  
Triplet Ground State ◽  
Nv Center

Paramagnetic defects in solids have become attractive systems for quantum computing as well as magnetometry in recent years. One of the leading contenders is the negatively charged nitrogen-vacancy defect (NV center) in diamond proposed to be highly promising with respect the afore-mentioned applications. In our study we investigate the NCVSi defect in 3C, 4H and 6H SiC as alternative choices with superior properties. Electronic structure of NV center in SiC exhibits S = 1 triplet ground state with the possibility of optical spin polarization. On the other hand, our results obtained by density functional theory calculations may contribute to unambiguously identify the possible defect configurations.

Tetracyanonickelate(II) compounds of some (tetraazamacrocycle)nickel(II) cations. The structure of catena-Di(μ-cyano)dicyano(N-meso-5,7,7,12,14,14-hexamethy1-1,4,8,11-tetraazacyclotetradeca-1, 11-diene)dinicke1(II) hydrate

1984 ◽  
Vol 37 (9) ◽  
pp. 1799 ◽  
Author(s):  
GJ Gainsford ◽  
NF Curtis
Keyword(s):  
Infrared Spectra ◽  
Ground State ◽  
Singlet Ground State ◽  
Ring Size ◽  
Triplet Ground State ◽  
Coordination Environment ◽  
Magnetic Susceptibilities ◽  
X Ray ◽  
A Chain ◽  
Tetracyanonickelate Compounds

Tetracyanonickelate(II) compounds of several (tetraazamacrocycle)nickel(II) cations have been prepared. The structure of the N-meso-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca- 4,11-diene, hmtd, compound [Ni(hmtd)Ni(CN)4].H2O has been determined by X-ray diffractometry [monoclinic, a 1780.3(3), b 1063.41(7), c 1409.3(2) pm, β 120.54(1)�, 24, space group C2/c, R 0.021, Rw 0.030 for 2178 reflections] and shows a chain polymeric structure with trans singlet ground state [Ni(CN)4]2- groups linking parallel stacked triplet ground state [Ni(hmtd)]2+ groups. The triplet ground state nickel(II) ions have a tetragonally elongated coordination environment [Ni-N (mean macrocycle) 204.5(1) pm, Ni-N (N≡C) 220.7(1) pm]. Tetracyanonickelate compounds of macrocycles related to hmtd but with different substituents, macrocycle ring size, and/or numbers of imine and amine donor groups were prepared. Some are diamagnetic, with discrete cation and anion, while others are similar to the hmtd compound, and for the latter, tetragonal distortions were evaluated from the reflectance spectra. Magnetic susceptibilities and infrared spectra are reported.

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