ECNU-23: DO Family

Periodic Building Unit (PerBU):

Layer symmetry

2D cell parameters

a = 10.50 Å

b = 13.86 Å

gamma = 90°

To facilitate understanding of the connectivity patterns shown below, O atoms that connect to a single row of 4-ring units have been highlighted in the CFI layer shown to the right.

Intergrowth Family ECNU-23

2-dimensional disorder of the units connecting ordered layers

Periodic Building Unit

Connecting unit

	Connecting unit	4-ring

References


		Liu, X., Yi Luo, Y., Mao, W., Jiang, J., Xu, H., Han, L., Junliang Sun, J. and Wu, P.
			"3D electron diffraction unravels a new zeolite ECNU-23 from the “pure” powder sample of ECNU-21"
			Angew. Chem. Int. Ed., 59, 1166-1170 (2020)

Connectivity pattern

Examples

Positions of 4-ring unit connectors in a row
There are two possible positions for a row of 4-ring units above the CFI layer. The position of the first 4-ring unit (along a) determines the positions of all the other 4-ring units in that row.

Symmetry Operations	Translation	Comment	Image
	0	4-ring units in position 1
	1/2a	4-ring units in position 2


Second row identical to first with no shift along a	Second row shifted by 1/2a with respect to first

Examples

Disorder along c: stacking of the layers of connectors
Each CFI layer (green) is generated from the previous one (gray) by a mirror plane. The CFI layers themselves are ordered along c. However, the 4-ring units in the connecting layers can also be disordered along c, making the disorder 2-dimensional (along both b and c). The rows of 4-ring unit connectors can be stacked along the [001] direction using either of the following connectivity patterns

Symmetry Operations	Translation^*	Comment	Image
	0a + 1/2b
	1/2a +1/2b

^* relative to the previous layer of connectors

Effect on channel system
The disorder does not block the channel system. However, the 8-ring channel becomes sinusoidal when both 4-ring positions are present in a single layer of 4-ring units (i.e. it is no longer straight as in polymorph A or B below).

Simplest ordered end-members

The color of the connectors between the layers reflects those shown in the tables above.


Polymorph ECNU-23_A

Cell Parameters:	orthorhomobic	C m m m (# 65)
	a = 22.3774 Å	b = 13.8579 Å	c = 10.5004 Å
	α = 90.0000°	β = 90.0000°	γ = 90.0000°
	Volume =	3256.2 Å³
Framework Density (FD_Si):	17.2

	Ring sizes (# T-atoms):	12 8 6 5 4
	Channel dimensionality:	Topological (pore opening > 6-ring): 2-dimensional

Maximum diameter of a sphere:
	that can be included	7.06 Å
	that can diffuse along	a: 2.3 Å	b: 3.75 Å	c: 5.7 Å
		addional volume data

Composite Building Units:


mtt	cas	non	ton

In this space group and setting, the ordered connecting rows are along [001] and the layers are stacked along [100]

	Note: This polymorph has NOT been observed as a pure ordered material


Polymorph ECNU-23_B

Cell Parameters:	orthorhombic	I m m m (# 71)
	a = 21.9415 Å	b = 13.4744 Å	c = 10.1491 Å
	α = 90.0000°	β = 90.0000°	γ = 90.0000°
	Volume =	3000.6 Å³
Framework Density (FD_Si):	18.6

	Ring sizes (# T-atoms):	12 8 6 5 4
	Channel dimensionality:	Topological (pore opening > 6-ring): 2-dimensional

Maximum diameter of a sphere:
	that can be included	6.32 Å
	that can diffuse along	a: 1.86 Å	b: 3.69 Å	c: 5.09 Å
		addional volume data

Composite Building Units:


mtt	cas	non	ton

In this space group and setting, the ordered connecting rows are along [001] and the layers are stacked along [100]

	Note: This polymorph has NOT been observed as a pure ordered material


Polymorph ECNU-23_C

Cell Parameters:	orthorhombic	C m c m (# 63)
	a = 10.3101 Å	b = 27.3563 Å	c = 22.2010 Å
	α = 90.0000°	β = 90.0000°	γ = 90.0000°
	Volume =	6261.7 Å³
Framework Density (FD_Si):	17.9

	Ring sizes (# T-atoms):	12 8 6 5 4
	Channel dimensionality:	Topological (pore opening > 6-ring): 2-dimensional

Maximum diameter of a sphere:
	that can be included	6.74 Å
	that can diffuse along	a: 5.74 Å	b: 3.65 Å	c: 1.97 Å
		addional volume data

Composite Building Units:


mtt	cas	non	ton

In this space group and setting, the ordered connecting rows are along [100] and the layers are stacked along [001]

	Note: This polymorph has NOT been observed as a pure ordered material