Showing papers by "Alexander J. Blake published in 1997"
459 citations
TL;DR: In this paper, a three-dimensional network based upon a cyclobutane-linked tetrapyridyl ligand was constructed by 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,20,21,22,23,24,25,26,27,28,29,30,31,33,34
175 citations
TL;DR: In this paper, the authors describe the factors influencing the observed structures of interpenetrating networks in the context of bipyridyl ligands in interlocking copper-heterocycle adamantoid arrays.
148 citations
TL;DR: In this paper, a complex consisting of co-ordinated and======hydrogen bonded 4,4′-bipy, respectively, to form two-dimensional rectangular grid sheets, has been isolated and structurally characterized.
Abstract: The complex
[Cu(µ-4,4′-bipy)(H
2
O)
2
(FBF
3
)
2
]·4,4′-bipy
(4,4′-bipy = 4,4′-bipyridine), in which copper
atoms are linked by Cu–4,4′-bipy–Cu and
Cu–OH
2
···
4,4′-bipy
···
H
2
O–Cu assemblies, involving co-ordinated and
hydrogen bonded 4,4′-bipy, respectively, to form two-dimensional
rectangular grid sheets, has been isolated and structurally
characterised.
141 citations
TL;DR: In this paper, an undulating polycatenated molecular ladder structure involving fully interwoven two-dimensional sheets was characterized by X-ray diffraction studies, which showed an unweighted polycyclic structure.
115 citations
TL;DR: In this article, the authors gave the corresponding arylimido derivatives and the corresponding terttert-butylpyridine and pyridine derivatives respectively in good yields.
Abstract: Treatment of TiCl
4
with Bu
t
NH
2
(6
equivalents) followed by addition of bpy (2 equivalents,
4-tert-butylpyridine) or pyridine (py) (2 or 4 equivalents)
afforded the five- or six-co-ordinate tert-butylimido
complexes
[Ti(NBu
t
)Cl
2
(bpy)
2
] or
[Ti(NBu
t
)Cl
2
(py)
n
]
(n = 2 or 3*) respectively in good yields.
Reaction of [Ti(NBu
t
)Cl
2
(py)
3
] with
RNH
2
gave the corresponding arylimido derivatives
[Ti(NR)Cl
2
(py)
3
] (R = Ph,*
C
6
H
4
Me-4,*
C
6
H
4
NO
2
-4,*
C
6
H
3
Me
2
-2,6 or
C
6
H
3
Pr
i
2
-2,6). Addition
of
tmen or pmdien to
[Ti(NBu
t
)Cl
2
(py)
n
]
(n = 2 or 3 respectively) gave the
corresponding
bi- or tri-dentate amine complexes,
[Ti(NBu
t
)Cl
2
(tmen)] or
[Ti(NBu
t
)Cl
2
(pmdien)]*
(tmen = Me
2
NCH
2
CH
2
NMe
2
,
pmdien = N,N,N′,N
″,N″
-pentamethyldiethylenetriamine). Complexes labelled * have been
crystallographically characterised.
103 citations
TL;DR: The ligand 2,7-diazapyrene (L) is used to construct three and============two-dimensional arrays with Cu============ I====== and Ag============ 1.
95 citations
TL;DR: In this article, twenty new copper-lanthanoid complexes have been prepared and a structural characterization of eleven of these complexes gave some indications of how the structure is controlled in these compounds.
Abstract: Twenty new copper–lanthanoid complexes have been prepared. The
route involves reaction of preformed copper pyridonate complexes with
hydrated lanthanoid nitrates in a variety of solvents. Structural
characterisation of eleven of these complexes gave some indications of
how the structure is controlled in these compounds. Reaction of
[Cu
6
Na(mhp)
12
][NO
3
]
(mhp = 6-methyl-2-pyridonate) with hydrated lanthanum
nitrate in CH
2
Cl
2
leads to a high-nuclearity
complex containing a Cu
12
La
8
core. The twelve Cu
atoms are arranged in a cuboctahedron surrounded by a cube of eight La
atoms. Similar reactions involving 6-chloro-, 6-bromo- and
6-fluoro-2-pyridonate led to tetranuclear complexes which fall into
three distinct structural groups. Consideration is given to the factors
governing the choice of structural group.
60 citations
TL;DR: The structure of dimethylaluminium tetrahydroborate has been investigated by X-ray diffraction of single crystals at low temperatures as discussed by the authors, with a transition temperature in the range of 180-195 K.
Abstract: The structures of several aluminium tetrahydroborates have been
investigated, primarily by X-ray diffraction of single crystals at low
temperatures. The structure of dimethylaluminium tetrahydroborate has
been shown to consist of helical polymeric chains in which
Me
2
Al and BH
4
units alternate. The BH
4
groups exhibit bidentate ligation with respect to each of the adjacent
metal atoms in a manner reminiscent of [MeZnBH
4
] and
Be(BH
4
)
2
. Solid aluminium tris(tetrahydroborate)
exists in two phases with a transition temperature in the range
180–195 K. Each phase is made up of discrete
Al(BH
4
)
3
units in which the angle between
AlB
2
and Al(µ-H)
2
B planes is close to 90°
and which conform within the limits of experimental error to
D
3h
symmetry; in the α phase these
molecular units are disposed around a 2
1
crystallographic
screw axis.
53 citations
TL;DR: A new type of imido compound containing atripodal dianionic ligand is reported in this article, which effects the remarkably======¯¯¯¯selective trimerisation of MeNC.
46 citations
TL;DR: In this paper, a tris(2-aminoethyl)amine with 2,6-diformyl-4-methylphenol compound has been proposed and its crystal structure showed the arms to be arranged such that a non-crystallographic threefold axis passes through the bridgehead N atom.
Abstract: A novel tripodal ligand (H
3
L
1
) has been prepared
by condensation of tris(2-aminoethyl)amine with 2,6-diformyl-4-methylphenol
in MeOH. The compound has three equivalent side-arms, each containing four
possible donor groups, an imine N atom, a phenol O atom and two O-donors
from an acetal group. The crystal structure showed the arms to be arranged
such that a non-crystallographic three-fold axis passes through the
bridgehead N atom. Reaction of H
3
L
1
with lanthanoid
perchlorate salts resulted in the isolation of two series of complexes.
With early lanthanoids compounds of stoichiometry
[Ln(H
3
L
1
)(H
2
O)][ClO
4
]
3
were obtained and the compounds with Ln = La and Pr
have been structurally characterised. The lanthanoid site in these
complexes is ten co-ordinate, with a geometry which can be related to an
icosahedron. For later lanthanoids, complexes of stoichiometry
[Ln(H
3
L
1
)][ClO
4
]
3
are found in
which the lanthanoid site is nine-co-cordinate, with a tricapped
trigonal-prismatic geometry. The complex with Ln = Y has been
characterised by diffraction techniques. Mass spectroscopic studies
indicated that the acetal functions within H
3
L
1
are
stabilised by co-ordination to the lanthanoid metals. Reaction of the
complex
[La(H
3
L
1
)(H
2
O)][ClO
4
]
3
with nickel(II) perchlorate led to a novel
heterobimetallic complex in which both La and Ni are encapsulated within
the tripodal ligand.
TL;DR: The polymeric complexes [Ag2([24]aneS8)(CF3SO3)2- (MeCN)2]∞ and [Ag([16]-aneS4)(BF4)]∞ show infinite ladder and layered structures respectively, with the thioether crown controlling the multi-dimensional architecture as mentioned in this paper.
TL;DR: In this article, the structure of a charge-transfer network is visualized as an infinite chain structure with asymmetric diiodine bridges between neighbouring macrocycles leading to an infinite-chain structure.
Abstract: The charge-transfer complexes
2[9]aneS
3
·4I
2
([9]aneS
3
= 1,4,7-trithiacyclononane),
[12]aneS
4
·I
2
([12]aneS
4
= 1,4,7,10-tetrathiacyclododecane),
[14]aneS
4
·I
2
,
[14]aneS
4
·2I
2
([14]aneS
4
=
1,4,8,11-tetrathiacyclotetradecane),
[16]aneS
4
·I
2
and
[16]aneS
4
·4I
2
([16]aneS
4
= 1,5,9,13-tetrathiacyclohexadecane)
have been prepared by slow evaporation of solutions containing
I
2
and the appropriate thioether macrocycle in
CH
2
Cl
2
. The structure of
2[9]aneS
3
·4I
2
shows two independent
macrocycles in the asymmetric unit which are linked by a diiodine
bridge. Asymmetric units are linked by
I · · · I and
S · · · I interactions to
form an extended array of linked macrocycles. The single-crystal
structure of [12]aneS
4
·I
2
features an
infinite chain structure formed by alternating [12]aneS
4
and
I
2
molecules. The structure contains both symmetric and
asymmetric diiodine bridges. Although the 1∶1 adduct
[14]aneS
4
·I
2
can also be described as a
one-dimensional infinite chain structure with asymmetric diiodine
bridging, the structure is better visualised as alternating layers of
macrocycle and iodine spanned by short contacts of 3.335(4)
A. The adduct [14]aneS
4
·2I
2
shows two independent macrocycles each co-ordinated to two I
2
molecules. The charge-transfer network consists of chains of molecules
with alternating orientations. The single-crystal structure of a third
1∶1 adduct [16]aneS
4
·I
2
contains only
symmetrical diiodine bridges between neighbouring macrocycles leading to
an infinite chain structure. The compound
[16]aneS
4
·4I
2
is the first example of a
tetradentate macrocycle which incorporates I
2
bound to all
four S atoms. The single-crystal structure shows four terminal
I
2
molecules co-ordinated to the four S donors of the
macrocycle. Molecules are linked into interwoven sheets by
I · · · I interactions of
3.639(2) A. The formation enthalpies (ΔH)
and constants (K) of 1∶1 adducts obtained by treating
various thioether macrocycles with I
2
in
CH
2
Cl
2
have been determined by electronic
spectroscopy. The Fourier-transform Raman spectra for all the
charge-transfer adducts have been recorded in
CH
2
Cl
2
solutions at different concentrations. The
Raman frequencies of the ν(I–I) vibrations show good
correlation with the measured formation enthalpies ΔH.
TL;DR: In contrast to the closely related species, individual molecules have square-pyramidal geometry as mentioned in this paper and the corresponding compounds 2 and 3 are isostructural but, in contrast to these closely related compounds, individual molecule have square pyramids.
Abstract: Oxidative addition between
(biphenyl-2,2′-diyl)phenylantimony(III),
Sb(2,2′-C
12
H
8
)Ph 1 and Br
2
or
SO
2
Cl
2
gave
Sb(2,2′-C
12
H
8
)PhBr
2
2 and
Sb(2,2′-C
12
H
8
)PhCl
2
3,
respectively, while the corresponding fluoride
Sb(2,2′-C
12
H
8
)PhF
2
4 and the
thiocyanate
Sb(2,2′-C
12
H
8
)Ph(NCS)
2
5 were
obtained by metathesis reactions between 3 and KF and KSCN,
respectively Compounds 2 and 3 are isostructural but, in contrast to
the closely related SbPh
3
X
2
species, individual
molecules have square-pyramidal geometry Again in contrast to
SbPh
3
X
2
compounds, secondary
antimony–halogen interactions trans to the apical carbon
atom lead to solid-state dimers, implying Lewis acidity at antimony
Antimony in the thiocyanate 5 showed similar square-pyramidal geometry
with N-bonded thiocyanate groups but bridging by one thiocyanate again
gives dimers in the solid Oxidative addition between SbPhCl
2
and tetrachloro-ortho-benzoquinone in ether solution gave the
tetrachlorocatechol analogue of 3 as a six-co-ordinate ether solvate,
SbPh(o-O
2
C
6
Cl
4
)·OEt
2
6 If the weak bond to ether is ignored, antimony again has
square-pyramidal geometry but formation of the adduct again points to
antimony Lewis acidity A non-solvated substituted catecholate,
SbPh(o-O
2
C
6
H
2
Bu
t
2
-3,5)Cl
2
8, was also synthesized but crystals
suitable for X-ray diffraction could not be obtained
TL;DR: A tetrahydrofuran suspension of silver(I) oxide reacted with Hhfpd (1, 1,1,5, 5,5-hexafluoropentane-2,4-dione) to give in
Abstract: A tetrahydrofuran suspension of silver(I) oxide reacted
with Hhfpd (1,1,1,5,5,5-hexafluoropentane-2,4-dione) to give in
situ ‘[Ag(hfpd)]’ after removal of the solvent in
vacuo. Addition of equimolar ratios of multidentate amines to
toluene solutions of the ‘[Ag(hfpd)]’ led to the isolation
of several hexafluoropentanedionatosilver(I) complexes,
[Ag(hfpd)(L–L)]
[L–L = Me
2
NCH
2
CH
2
NHMe (trimen) 1,
Me
2
N(CH
2
)
2
NMe(CH
2
)
2
NMe
2
(pmdien) 2 or
Me
2
N(CH
2
)
2
NMe(CH
2
)
2
NMe(CH
2
)
2
NMe
2
(hmten) 3].
Addition of only half a molar equivalent of hmten to a toluene solution
of ‘[Ag(hfpd)]’ led to the synthesis of
[Ag(hmten)][Ag(hfpd)
2
] 4. The products have been
characterised by a variety of methods including microanalysis, IR,
1
H and 13
C NMR spectroscopy and mass spectrometry
and all complexes dissolve readily in supercritical carbon dioxide.
Complexes 2 and 4 have been further characterised by X-ray
crystallography. The structure of 2 contains a monomeric
five-co-ordinate silver(I) cation in which the two chelating
oxygens and two of the three amine nitrogens are in an almost planar
arrangement. In comparison, the structure of 4 reveals a
charge-separated salt; one of the silver atoms is exclusively
co-ordinated to two hfpd ligands in a pseudo-tetrahedral arrangement,
whilst the other is encapsulated by an hmten molecule.
TL;DR: The second-order Jahn-Teller distortion of the titanium imido complexes was investigated in this article, where the authors showed that the deviation of the µ-imido complexes from coplanarity with the second order Jahn Teller distortion can be attributed to a second order jahn-teller distortion.
Abstract: Reaction of the titanium imido complexes
[Ti(NR)Cl
2
(py)
3
]
(R = Bu
t
,
C
6
H
3
Me
2
-2,6 or
C
6
H
3
Pr
i
2
-2,6;
py = pyridine) with 2 equivalents of lithium aryloxide
Li[OC
6
H
3
R′
2
-2,6]
(R′ = Me, Pr
i
or Bu
t
) afforded
the mononuclear four- or five-co-ordinate or binuclear four-co-ordinate
complexes
[{Ti(NR)(OC
6
H
3
R′
2
-2,6)
2
(py)
n
}
m
]
(m = 1, n = 1 or 2;
m = 2, n = 0) depending on
the identity of R and R′. The crystal structures of
[Ti
2
(µ-NBu
t
)
2
(OC
6
H
3
Me
2
-2,6)
4
] 1 and
[Ti(NC
6
H
3
Me
2
-2,6)(OC
6
H
3
Me
2
-2,6)
2
(py)
2
] have been
determined. Extended-Huckel molecular orbital calculations for
models of 1 showed that the deviation of the µ-imido
Bu
t
substituents from coplanarity with the
Ti
2
N
2
core in this and some related species can be
attributed to a second-order Jahn–Teller distortion.
TL;DR: In this paper, the X-ray crystal structure and NMR properties of the imidazole ring were discussed in detail, and the triplet nitrene intermediate was inserted into the CH bond.
Abstract: Flash vacuum pyrolysis (FVP) of the azide 4 leads to
imidazo[1,2-a]benzimidazole 8 exclusively, via highly
regioselective insertion of the triplet nitrene intermediate 5 into the
2-CH bond of the imidazole ring. The X-ray crystal structure and NMR
spectroscopic properties of 8 are discussed in detail.
TL;DR: An S-linked, heterocyclic calix[3]arene analogue 2 is prepared by condensation of a dichloro-1,3,5-triazine with sulfide ion as mentioned in this paper.
TL;DR: The reaction of 1,3-dimethyl ether with 1,tert-butylcalix (4) with sodium======¯¯¯¯hydride in tetrahydrofuran affords the dimeric metallocalixarene species, which possesses a novel structure in which ions are coordinated in two very different environments.
TL;DR: A systematic synthetic route to the hexanuclear cluster compound has been elaborated in this paper, in which a number of stable intermediates have been isolated and============characterised, and the molecular structure of one of the isomers has been established by single-crystal X-ray crystallography.
Abstract: A systematic synthetic route to the hexanuclear cluster compound
[Ru
6
C(CO)
13
(η
5
-C
5
H
3
Ph
2
)(µ
3
-CPh)] has been elaborated in
which a number of stable intermediates have been isolated and
characterised. The reaction of [Ru
6
C(CO)
17
] with
Me
3
NO and phenylacetylene afforded the alkyne derivative
[Ru
6
C(CO)
15
(PhC
2
H)] 1. Further
treatment of 1 with Me
3
NO and an excess of
phenylacetylene resulted in the formation of two isomers
[Ru
6
C(CO)
14
{C(Ph)CHC(Ph)CH}] 2
and [Ru
6
C(CO)
14
{C(Ph)CHCHC(Ph)}]
3. Both contain five-membered metallocyclic rings formed by the
head-to-head coupling of phenylacetylene in one isomer and the
head-to-tail coupling in the other. Reaction of isomer 2 with
Me
3
NO and phenylacetylene leads to
[Ru
6
C(CO)
13
(η
5
-C
5
H
3
Ph
2
)(µ
3
-CPh)] 4. The molecular
structure of one of the isomers, 3, has been established by
single-crystal X-ray crystallography.
TL;DR: The arenealkyne clusters RU6C(CO)12(η6-C6H6)(η3-C2Me2) as discussed by the authors have been prepared and characterised by single crystal X-ray diffraction, and their crystallographic packing motifs analysed.
TL;DR: In this paper, the reaction of hydrated lanthanide(III) chloride (LnCl3·6H2O) with tris-(2-aminoethyl)amine and the sodium salt of an α-ketocarboxylic acid afforded the trinuclear species [(LnL)2Na]+ which, on removal of Na+, aggregate further in MeOH to yield the neutral eight-coordinate cyclic tetranuclear species [Ln4(L1)4] (LbIII or YbIII), and the linear polymer
Abstract: Reaction of hydrated lanthanide(III) chloride (LnCl3·6H2O) with tris-(2-aminoethyl)amine and the sodium salt of an α-ketocarboxylic acid afforded the trinuclear species [(LnL)2Na]+ which, on removal of Na+, aggregate further in MeOH to yield the neutral eight-co-ordinate cyclic tetranuclear species [Ln4(L1)4] (Ln = YbIII or YIII), and the linear polymer [Y2(L2)2(MeOH)]∞ with alternating eight- and nine-co-ordinate YIII centres: recrystallisation of adducts of [L1]3– from H2O affords the nine-co-ordinate mononuclear species [Ln(L1)(OH2)2] (Ln = SmIII or GdIII).
TL;DR: The crystal structure of (±)-1,2;4,5-di-O-cyclohexylidene myo-inositol, refined to R = 2.9%, shows interestingly disordered (flip-flop) hydrogen bonding.
TL;DR: In this article, it was shown that unless stringent precautions are taken to exclude moisture there is cleavage of the oxygen bridge to give solutions which contain both the hydroxo species, SbR 3 (OH)X, and the original bridged compound.
TL;DR: In this article, it was found that NEt3 is a catalyst of this reaction, which results in the formation of complexes [Cp2NbH2(HAsEt2)(HPi−Pr2)2] and [BH3A2(HPPr2−i].
TL;DR: In this article, the octahedral metal skeleton common to 1, 2, 4, and 5 has undergone rearrangement to a monocapped square pyramid, and the molecular structures of 3, 5, and 6 have been established in the solid state by single-crystal X-ray diffraction analysis.
TL;DR: In this paper, the thermal properties of high-quality nonlinear optical single crystals of 4-nitro-4′-methylbenzylidene aniline (NMBA) have been measured in various temperature ranges.
Abstract: The thermal properties of high-quality nonlinear optical single crystals of 4-nitro- 4′-methylbenzylidene aniline (NMBA) have been measured in various temperature ranges. The specific heat was measured in the range from 273 to 373 K by differential scanning calorimetry and was found to obey the relationship Cp=2.3×10−3 T+0.487 J g−1 K−1. The peak melting point was detected at a temperature of 402 K with a corresponding enthalpy of melting ΔHm of 113.63 J g−1. Principal thermal expansion and thermal conductivity coefficients were determined at different temperatures. For example, at room temperature (295 K) they were α1=1.274×10−4 K−1, α2=0.826×10−4 K−1, and α3=0.239×10−4 K−1. The principal thermal conductivity coefficients were k1=0.40 W m−1 K−1, k2=0.19 W m−1 K−1, and k3=0.21 W m−1 K−1 and these values were independent of temperature up to 370 K.
TL;DR: In this article, the title compound, C 10 H 20 S 4.4I 2, possesses crystallographically imposed inversion symmetry and has all four S donor atoms coordinated to diiodine molecules.
Abstract: The title compound, C 10 H 20 S 4 .4I 2 , [14]aneS 4 .4I 2 , possesses crystallographically imposed inversion symmetry and has all four S donor atoms coordinated to diiodine molecules. The principal geometric parameters for the two inequivalent pairs of interactions are S-I 2.803 (2) and 2.880(2)A, I-I 2.7894 (8) and 2.7571(10)A, and S-I-I 177.71(5) and 172.50(4)°. Molecules are linked by S...I and I...I intermolecular contacts to form an infinite three-dimensional lattice.